yossarian

open source interloper; attracts bugs easily

אַ ביסל ייִדיש־פּאָסטינג

Public Key

npub1srpm3cp2mnr5efng42p2ae594h3al2xhw0u87ef27q7x23u9cj4q3uh23s

NIP-05 Address

[email protected]

Profile Code

nprofile1qqsgpsacuq4de36v5e524q4wu6z6mc7l4rth87rlv540q0r9g7zuf2spz4mhxue69uhhyetvv9ujuerfw36x7tnsw43qpk0sm3

Publishing to

relay.ditto.pub

Author Public Key

npub1srpm3cp2mnr5efng42p2ae594h3al2xhw0u87ef27q7x23u9cj4q3uh23s

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Last Notes

2026-08-11 14:36:00 GMT

following PEP 833, Python packaging now considers the HTML index representation frozen!
I’m really happy we got this out: IMO it’s a small but very important step towards nudging clients to prefer the JSON index, which is better in every regard.
https://blog.pypi.org/posts/2026-08-11-html-index-is-frozen/

2026-08-04 23:45:47 GMT

my keynote from europython is online!
https://youtu.be/wMPe_KepOjc
#python #europython

2026-08-01 21:28:33 GMT

zizmor 1.29.0 is released!
this release comes with a number of enhancements and bug fixes, but the big one is that we now support auditing pre-commit inputs! support is limited to just a single audit for now, but will expand over subsequent releases.
full notes: https://docs.zizmor.sh/release-notes/#1290

2026-08-01 21:00:41 GMT

created another small `gh` extension, to migrate open issues/PRs across milestones:
https://github.com/woodruffw/gh-mm
(for whatever reason, GitHub's own UI can't do this in bulk. I wish it could!)

2026-07-29 17:17:26 GMT

we deleted support for three entire compression schemes in uv 0.12, and nobody has noticed (so far). I call that a win.
(Also a strong signal that Python packaging *is* - slowly - becoming a more uniform and standards-conforming ecosystem.)

2026-07-07 12:58:23 GMT

You shouldn’t trust Trusted Publishing
https://blog.yossarian.net/2026/07/07/You-shouldnt-trust-trusted-publishing
#python #security #oss

2026-06-20 00:18:22 GMT

this new interaction limit feature from GitHub is great, except that it's inexplicably only ever temporary. I really don't want to have to remember to re-toggle this every 6 months!
https://media.infosec.exchange/infosec.exchange/media_attachments/files/116/779/560/544/240/071/original/1557057152a13903.png

2026-06-15 23:11:10 GMT

i’m excited and honored to be a keynote speaker at @nprofile…za49 this year!
https://ep2026.europython.eu/session/securing-python-for-the-next-decade

2026-06-09 22:10:27 GMT

I have been very critical about npm and JavaScript as a whole, so I also want to lavish praise where it is due: this is a great change, and demonstrates serious appetite for fixing things/making hard decisions in the interest of security:
https://github.blog/changelog/2026-06-09-upcoming-breaking-changes-for-npm-v12/

2026-06-08 15:32:14 GMT

I wrote a new post for the Astral blog about how we’re building more vulnerability and malware defenses directly into uv:
https://astral.sh/blog/uv-audit

2026-03-09 13:19:55 GMT

I put together a more detailed AI contribution policy for zizmor: https://github.com/zizmorcore/.github/blob/main/AI_POLICY.md

2025-12-27 20:12:27 GMT

another entry for the ignominious list of pgp fucky wuckies:
https://gpg.fail

2025-12-13 16:56:27 GMT

Dependency cooldowns, redux
https://blog.yossarian.net/2025/12/13/cooldowns-redux
#security #oss

2025-11-29 22:05:47 GMT

from PostHog's post-mortem: the attacker-controlled packages were on npm for < 6 hours. I count that as another datapoint in support of cooldowns!
ref: https://posthog.com/blog/nov-24-shai-hulud-attack-post-mortem

2025-11-24 15:22:57 GMT

i’m increasingly of the opinion that we’re at a “breakout energy” stage with malware in the JS ecosystem, meaning that we’ve passed the point where we can assert with some confidence that some percent of popular dependencies aren’t actively compromised at any given point.
This seems bad, and critically worse than risks around typosquatting etc., precisely *because* these packages are already embedded in dependency chains.

2025-11-21 14:45:51 GMT

We should all be using dependency cooldowns
https://blog.yossarian.net/2025/11/21/We-should-all-be-using-dependency-cooldowns
#security #oss

2025-10-07 21:13:29 GMT

how does this even happen. thanks github
https://media.infosec.exchange/infosec.exchange/media_attachments/files/115/334/943/125/672/564/original/2a0e1eaab7ad9c9c.mp4

2025-08-14 19:20:36 GMT

super excited to have this land: you can now pull project status markers (PEP 792) from PyPI's APIs!
https://blog.pypi.org/posts/2025-08-14-project-status-markers/
#python #pypi

2025-06-30 19:30:25 GMT

zizmor v1.11.0 is released!
this is a much smaller release than v1.10.0, but it comes with an experimental feature that's been in the works for a long time: LSP support!
with `zizmor --lsp` you can now integrate zizmor directly into your editor/IDE. we even have an (experimental) vscode extension already: https://marketplace.visualstudio.com/items?itemName=zizmor.zizmor-vscode
see the full notes here: https://docs.zizmor.sh/release-notes/
#rust #security #opensource #github
https://media.infosec.exchange/infosec.exchange/media_attachments/files/114/773/961/132/293/101/original/f9dae4ec123a725e.png

2025-05-30 18:28:42 GMT

npm is getting trusted publishing soon!
https://github.com/orgs/community/discussions/161015
helping build and design the original version of trusted publishing for PyPI is easily in the top 3 moments of my career so far -- it's really amazing to see it get adopted by RubyGems, Rust (in progress), and now the JS ecosystem.

2025-05-21 14:21:09 GMT

memory safety arrives on foot and leaves on horseback

2025-05-09 12:53:25 GMT

zizmor just hit a million downloads from PyPI alone! it continues to amaze and amuse me how Python packaging is one of the easiest ways to distribute non-Python tooling
(there isn't a single line of Python in zizmor besides helper scripts -- it's all Rust)
https://pepy.tech/projects/zizmor
https://media.infosec.exchange/infosec.exchange/media_attachments/files/114/477/962/207/929/467/original/63140ac0b688d90b.png

2025-05-05 16:50:04 GMT

- reply

@nprofile…r0kn yeah, that's a great point -- i've seen the same increase in quantity of articles and i can't really blame postcasters, newsletter writers, etc. if the sources themselves are also going downhill

2025-05-05 16:18:53 GMT

i have this nagging feeling that a lot of second-order content (podcasts, newsletters) in the infosec world is undergoing a marked, visible decline in quality as creators rely more and more on LLMs to summarize and editorialize their subjects

2025-05-01 13:35:31 GMT

my colleague @nprofile…hqyn has put out a new post on the @nprofile…7f46 blog on how we worked with @nprofile…xg7q's maintainers to slash PyPI test run times from ~160s to ~30s despite overall test counts growing by 17% (3900 to 4700+):
https://blog.trailofbits.com/2025/05/01/making-pypis-test-suite-81-faster/
this is some of my favorite kind of work: faster test suites means that developers run tests locally more often, and are less hesitant to add new tests (especially parametric ones). another great example of security and performance/reliability engineering dovetailing.
#opensource #security #python

2025-04-20 02:20:42 GMT

i've just released zizmor v1.6.0!
this release comes with a lot of bugfixes that have accumulated over the last month, plus some big new features:
1. there's a new audit, `forbidden-uses`, which allows users to configure allow/deny policies for third-party actions!
2. the `unpinned-uses` audit has been completely rewritten, and now also supports configuration (e.g. to give your own first-party actions a weaker pinning policy than "must be hashed")
3. there's a new `--format=github` mode, which emits GitHub annotations. these come with quite a few limitations, but may be useful to users who can't use `--format=sarif`!
plus much more; read the full notes here:
https://woodruffw.github.io/zizmor/release-notes/#v160
#rust #security #opensource #github

2025-04-07 16:56:47 GMT

i'm proud to announce that we've just released `pip-audit` v2.9.0, which includes support for Python's newly standardized lockfile format!
TL;DR: you can now pass `--locked` to `pip-audit` when auditing a project structure to collect `pylock.*.toml` files. these files are much faster to audit than `pyproject.toml` and similar sources, since they don't require us to perform any resolution!
release notes: https://github.com/pypa/pip-audit/releases/tag/v2.9.0
#python #security #opensource
https://media.infosec.exchange/infosec.exchange/media_attachments/files/114/297/730/135/843/929/original/ffe5ae2a575eef2f.png

2025-04-01 22:50:56 GMT

this makes me really happy: over 1/6th of the top (by download) Python projects are producing attestations!
that's a meteoric adoption rate, given that we only enabled attestation upload support on PyPI ~5 months ago!
tracker here: https://trailofbits.github.io/are-we-pep740-yet/
#python #opensource #security
https://media.infosec.exchange/infosec.exchange/media_attachments/files/114/265/130/332/836/152/original/354269ef9aa9a128.png

2025-03-11 00:41:35 GMT

zizmor v1.5.0 is released!
this release doesn't bring any new audits, but it does bring some high-demand CLI changes:
* zizmor now respects `.gitignore` by default, making local runs (against directories containing build state) much faster!
* `--no-progress` has been added and can be used to disable progress bars entirely
* `--color` has been added and can be used (along with environment variables) to force enable/disable ANSI colors
full release notes here: https://woodruffw.github.io/zizmor/release-notes/#v150
#rust #opensource

2025-02-21 17:26:07 GMT

i can think of few things more frustrating than being challenged for email MFA, clicking the button a bunch of times, getting no emails, and then suddenly getting 10+ MFA codes that have all been expired for over an hour

2025-02-19 04:31:32 GMT

TIL: Python package metadata has at least 4 different representations
https://yossarian.net/til/post/python-package-metadata-has-at-least-4-different-representations/
#til #python

2025-02-15 23:14:57 GMT

zizmor just hit 2k stars on GitHub! thank you to everybody who has sent me feedback and feature requests (and of course patches) so far!
https://media.infosec.exchange/infosec.exchange/media_attachments/files/114/010/442/514/470/993/original/ec714cd314111e85.png

2025-02-12 07:16:53 GMT

it blows my mind that the *official* way to build a multi-arch Docker image across a matrix is to YOLO a bunch of stuff through multiple layers of templates, action calls, and shell blocks held together with `jq` and prayers:
https://docs.docker.com/build/ci/github-actions/multi-platform/#distribute-build-across-multiple-runners

2025-01-30 15:00:24 GMT

you can now archive projects on PyPI!
this work was done by my teammate Facundo and is part of a larger multi-year arc of work dedicated to landing security and usability improvements on PyPI:
https://blog.trailofbits.com/2025/01/30/pypi-now-supports-archiving-projects/
#python #pypi #opensource

2025-01-13 20:11:27 GMT

just another day in the software mines
https://media.infosec.exchange/infosec.exchange/media_attachments/files/113/822/861/400/902/383/original/7c598e823c72443b.png

2025-01-13 16:22:42 GMT

excellent set of observations from Alex Gaynor on OSS funding:
https://alexgaynor.net/2025/jan/13/challenges-funding-open-source/

2025-01-10 16:50:19 GMT

Be aware of the Makefile effect
https://blog.yossarian.net/2025/01/10/Be-aware-of-the-Makefile-effect
#programming

2024-12-26 16:44:03 GMT

hi all, i'm doing another round of donations this year.
i'll match up to $2000 total and my company will match up to another $2000, so matching me will get your donation tripled.
here are some of the organizations i'm supporting:
* Anera: https://www.anera.org/ -- food and relief in Palestine, Lebanon, and Jordan
* HIAS: https://hias.org/ -- resettlement and support for immigrants around the word
* ProPublica: https://www.propublica.org/ -- investigative journalism in the public interest
* Python Software Foundation: https://www.python.org/psf-landing/ -- financially hosts and supports the development of Python
send me your donation receipt, and i'll send you a matching one (public or private, your choice!)

2024-12-26 04:00:36 GMT

ask not for whom the request pulls, it pulls for thee

2024-12-19 15:56:05 GMT

zizmor v0.10.0 is released!
this is a another pretty big release:
* online audits should be 30-40% faster in most cases, and up to 90% faster in some heavily cached cases
* @nprofile…g29s contributed another excellent audit for detecting potential cache poisoning vectors
* the github-env audit now supports analyzing PowerShell run bodies
* the overall quality/detail of the SARIF output is significantly improved
full notes here: https://github.com/woodruffw/zizmor/releases/tag/v0.10.0
#rust #security #opensource

2024-12-16 19:05:05 GMT

just had an interesting realization: one of the reasons people struggle to understand template injection in GHA is probably because lines like this:
```
echo "hello: ${{ expr }}"
```
...get lexed mentally as "variable expansion, followed by Jinja template."
in other words, people think the `$` comes from the shell and the `{{ }}` is the template syntax, and therefore the entire thing is quoted correctly.
in reality of course the entire `${{ .. }}` is template syntax, and has nothing to do with shell quoting/expansion rules. but `$` is mentally overloaded!
i wonder how much easier this would be to teach people if GitHub had chosen `@{{ ... }}` or even just `{{ }}` as their template syntax instead.
#security #opensource

2024-12-13 15:17:24 GMT

zizmor passed 1000 stars last night! pretty crazy for a project that i open sourced only ~6 weeks ago
https://github.com/woodruffw/zizmor
https://media.infosec.exchange/infosec.exchange/media_attachments/files/113/646/173/168/078/779/original/0e6eb25909a4bda5.png

2024-12-12 15:41:45 GMT

zizmor 0.9.0 is released!
some key changes:
* bugfixes/precision improvements around a handle of safe template patterns (e.g. `runner.temp`)
* precision improvements to our handling of matrices and matrix expansions, thanks to @nprofile…g29s
* the terminal interface has been reworked to use tracing spans internally, making it even more responsive
full release notes here: https://github.com/woodruffw/zizmor/releases/tag/v0.9.0
#rust #security #opensource
https://media.infosec.exchange/infosec.exchange/media_attachments/files/113/640/608/126/605/678/original/9526568ea6b8d047.mp4

2024-12-11 15:14:57 GMT

excellent summary from @nprofile…am0g on the PyPI side of the recent Ultralytics package compromise: https://blog.pypi.org/posts/2024-12-11-ultralytics-attack-analysis/
#python #security #opensource

2024-12-10 17:06:00 GMT

i think it's pretty interesting how "can a smartphone app handle 30s of internet connectivity, followed by 30s of non-connectivity, followed by 10s of connectivity" is still in 2024 a very strong proxy for "has the developer ever ridden the NYC subway"

2024-12-06 16:24:08 GMT

- reply

@nprofile…xg92 i haven't fully root-caused here, but it looks like they pivoted from the pull_request_target to another privileged workflow via a poisoned cache or similar, and there are plenty of workflows in their repo that seem to have contents: write or other persistence vectors
(the cache is just a hypothesis currently)

2024-12-06 16:11:57 GMT

- reply

@nprofile…xg92 ah yeah, i thought the wheel was published directly from the compromised workflow.
independent rebuilds would have caught this case since the attacker didn't bother to persist their changes, but FWICT with the permissions they got they could have opted to do that as well :-)

2024-12-06 14:58:52 GMT

- reply

@nprofile…xg92 not solved, for sure — I think the main things it would have done here are provided a simpler timeline and maybe given the maintainers an earlier notice, if they were monitoring their publishing identity. So maybe it wouldn’t have been as bad but attestations (and signing more generally) IMO fundamentally can’t stop this kind of stuff

2024-11-23 22:08:26 GMT

TIL: Backlinking to Fediverse accounts with meta tags
h/t to @nprofile…g0qy for this one!
https://yossarian.net/til/post/backlinking-to-fediverse-accounts-with-meta-tags/
#til #fediverse #mastodon #web

2024-11-21 01:27:38 GMT

TIL: Some surprising code execution sources in bash
https://yossarian.net/til/post/some-surprising-code-execution-sources-in-bash
#til #shell #security

2024-11-20 18:32:18 GMT

PyPI's support for attestations (PEP 740) now includes GitLab, extending support beyond the initial scope (which was GitHub). that means that, if you're a GitLab CI/CD user, you can now upload attestations to PyPI and the index will verify and re-serve them!
docs here: https://docs.pypi.org/attestations/producing-attestations/#gitlab-cicd
#pypi #python #security
https://media.infosec.exchange/infosec.exchange/media_attachments/files/113/516/708/090/316/612/original/4c179c2ffb85ef14.png

2024-11-19 15:59:08 GMT

Are we PEP 740 yet? now has a new category, colored in magenta, for top projects that come from source repos that PyPI doesn't support for attestations (yet!)
This will hopefully ameliorate some of the social pressure/confusion that people have (very reasonably!) expressed around the previous render: if a project is colored in magenta, that means PyPI doesn't support attestations (yet) from that host and thus the project can't reasonably be asked to support them itself.
And note: if you're a supply chain person who nags *any* project to enable attestations just because you want a little green checkbox on your VC-funded CRUD dashboard, I *will* find you and shame you.
https://trailofbits.github.io/are-we-pep740-yet/
#python #pypi #security
https://media.infosec.exchange/infosec.exchange/media_attachments/files/113/510/433/452/169/551/original/48b9e217aef7278f.png

2024-11-18 15:42:47 GMT

Security means securing people where they are
https://blog.yossarian.net/2024/11/18/Security-means-securing-people-where-they-are
#security #oss

2024-09-23 23:16:41 GMT

YAML: no loads() refused

2024-09-11 00:51:44 GMT

I think the single most important thing Maryland taught me was to put old bay on popcorn

2024-09-10 00:38:30 GMT

https://alexgaynor.net/2024/sep/09/signatures-are-like-backups/ great post from alex on why signatures are useless without verification

2024-09-09 17:03:43 GMT

https://media.infosec.exchange/infosec.exchange/media_attachments/files/113/108/673/333/910/556/original/5e38d1088e6bd40f.jpg

2024-08-02 13:39:41 GMT

if I had a nickel for every supply chain malware blog post where the “malware” is a script kiddy setup.py tweak and the “compromise” is “10 mirroring bots have downloaded it,” I would have several bucks at this point

2024-07-29 17:07:00 GMT

it's one of those plates-spinning-everything-is-fucked days

2024-07-23 20:44:23 GMT

i think it might finally be time to do the "vulnerability scores are fake and you should fire any vendor who sells/delivers them to you" post

2024-07-19 22:23:25 GMT

oh you like endpoint security? name every endpoint

2024-07-19 15:49:16 GMT

the costs will continue to be externalized until morale improves

2024-07-19 15:00:33 GMT

the S in EDR stands for security

2024-06-12 15:05:57 GMT

i'm often negative about GitHub Actions, so some positivity for once: being able to trigger workflows `gh workflow run` from my terminal is incredible, and saves me a ton of context switches
https://media.infosec.exchange/infosec.exchange/media_attachments/files/112/604/266/200/505/367/original/f8eb6bfc2832ef62.png

2024-06-07 16:28:09 GMT

periodic reminder: you cannot "pass" a security audit. anybody selling you a passable security audit is selling you a lie, and anybody selling you a product that has "passed' an audit is lying to you.
a security audit can uncover bugs, or not uncover bugs, and can (in the words of the recipient) demonstrate positive or negative qualities about the codebase. but it cannot be "passed" or otherwise *endorse* the product or program itself.

2024-05-15 15:59:51 GMT

threat supermodel

2024-04-03 21:46:59 GMT

when the static analysis is Good and Correct
https://github.com/github/codeql/issues/15942
https://media.infosec.exchange/infosec.exchange/media_attachments/files/112/209/478/756/094/467/original/ee1d7d53250889c5.png

2024-03-18 22:42:56 GMT

https://media.infosec.exchange/infosec.exchange/media_attachments/files/112/119/099/257/418/816/original/5380b75eadb80b1a.png
https://media.infosec.exchange/infosec.exchange/media_attachments/files/112/119/104/982/282/194/original/a78844c151eda01f.png

2023-08-27 22:36:23 GMT

giving myself a tension headache trying to think of a fish shell + Drag Race joke

2023-08-26 03:10:49 GMT

one of the worst things about the US is being somewhere, thinking “this is great, I wonder why a train doesn’t go here,” and discovering that a train *did* go there until it was torn up and replaced by a highway ~50 years ago

2023-08-02 22:04:10 GMT

my kingdom for a serialization format that doesn’t suck shit