19 comments

  • ataraxia937 1 hour ago
    This one again feels overblown, at least for servers. I just checked an org of over 200 GitHub repos. Node, Python, and C#. None of them are vulnerable... because none of them actually call the Brotli decoder. It's just not enabled by default on the server side, by the platforms themselves. This is much like the PHP bugs, where specific conditions have to be in play before you're actually vulnerable.

    For clients? Sure, that's a bigger risk. Patch them. But bad guys aren't attacking your clients unless the clients connect to them. Don't stay up late to fix this.

    (And yes, .NET is included here, because Microsoft's Brotli module is a binding for Google's vulnerable reference implementation.)

    • babuskov 20 minutes ago
      How did you check? Is there are PoC or some kind of command to run?
    • bbor 45 minutes ago
      I mean, I dare say the 4,200,000 Python servers built yesterday alone with this package might disagree...? https://pypistats.org/packages/brotli

      I can't find download numbers for extras, but it comes in the pretty dang innocuous-seeming `aiohttp[speedups]`, as well. Also `urllib3[brotli]`. Many, many people will be running these servers without recognizing the name of the library, especially in the agentic era.

      I might be missing something obvious in your message, cause I don't see why server/client is relevant. Why would a frontend app speak a protocol that the backend doesn't?

      • deathanatos 29 minutes ago
        That's just the total number of times that package was downloaded, which is completely unrelated to how many servers it appears in? Same with `aiohttp`: aiohttp can be used as a client library.

        Sure, people should check their dependency trees, and make informed decisions.

  • anonymous908213 2 hours ago
    I could do without every memory bug getting a cute sensational name and marketing push, I have to say.
    • aaronbrethorst 22 minutes ago
      We should start naming them like hurricanes: NIST creates a list of alphabetical names and assigns any CVE >= 9.0 with a name. Vulnerability Alex (CVE 9.4)
      • ks2048 2 minutes ago
        Vulnerability Zzyzx in a week
    • lovich 1 hour ago
      that ship sailed a while ago. Rowhammer is the first one I can remember
      • vinkelhake 1 hour ago
        Let's not forget about heartbleed!
        • judge2020 1 hour ago
          Back in the email days the virus authors named them, e.g. YouAreAnIdiot, ILoveYou
          • Waterluvian 38 minutes ago
            The Blaster virus was a fun one.
        • mhio 1 hour ago
          That was the first exploit logo I can recall
          • weinzierl 57 minutes ago
            The most memorable one for me is DirtyCOW.
  • ks2048 4 minutes ago
    Someone already created this website, for some reason,

    https://broccoli2shell.com/

  • hatthew 46 minutes ago
    I feel like normal security issues don't get much publicity. The PHP and eMudhra issues seemed severe, and worth publicity. But then with things like this, I'm not sure. Is this a severe issue? Or is it just a run of the mill issue that's only newsworthy because web security is on people's minds right now?
    • Gigachad 28 minutes ago
      The whole industry is on edge right now, and numbers wise the CVE count has exploded beyond belief. It's probably to take the side of caution, treat everything as important and update everything promptly rather than the old way of doing things where libraries are left months or years out of date until something happens.
  • rvanlaar 2 hours ago
    It looks like brotli <= 1.2.0 is vulnerable.

    The python package has already been updated to 1.2.1. https://pypi.org/project/brotli/1.2.1/

  • kccqzy 1 hour ago
    There’s apparently no writeup on exactly what was the fix. So I’m going to make a guess that this is the chromium commit that fixed the problem: https://source.chromium.org/chromium/chromium/src/+/224140d4...

    And this commit contained a refactoring from BROTLI_BOOL to BrotliDecoderErrorCode so the situation was that probably one of the error conditions previously simply returned false but needed more detail about what went wrong to continue safely.

    Well okay this change from `if (prev_ix < cur_ix)` to `if (prev_ix < cur_ix && cached_backward <= max_backward)` is also suspicious and could be an related or unrelated hardening fix.

  • adzm 2 hours ago
    Interestingly the commit that fixes this in brotli dates back to February https://github.com/google/brotli/commit/0ed4268a4401abcb4472...
    • cowlevel 2 hours ago
      OpenAI's tweet says it wasn't recognized as security relevant so wasn't important enough to make a release - until their agent realised it was.

      https://nitter.jaydenha.uk/OpenAI/status/2113766354386084338

      • dofm 1 hour ago
        Until their agent realised there was a good chance of a press release in it.
        • SV_BubbleTime 1 hour ago
          Chat, we need to constantly be justifying our absolutely absurd IPO. Use UltraMegThink and reference the ExploitToGetUsRegualtoryCapture.md. kkthnx
  • Sytten 2 hours ago
    Since I checked Rust servers should be fine since the brotli crate is not a binding on the C.
    • doodlesdev 10 minutes ago
      Apparently it doesn't contain a binding to the C library, but it does contain some compatibility and shares design decisions with it. In other words, it's not a clean-room implementation from the spec, but rather it's a port. Since this RCE is triggered by a OOB access, it's unlikely to have made it into the crate, but it's good to keep these things in mind.
  • kylepomykala 1 hour ago
    They just keep coming, don't they?
    • Gigachad 56 minutes ago
      For as long as we still have C code accessible to the internet.
    • hoppp 1 hour ago
      Never gonna stop. Consider it normal. Hey, at least humans still have a job. Incident response
      • awakeasleep 1 hour ago
        Let's not kid ourselves, llm's are already doing the incident response for this in many infrastructure teams
        • chelmzy 17 minutes ago
          I would love to hear your definition of this. Are llms used to aid in incident response? 100%. Why would I sit there and manually review data from multiple sources when I could have an agent pull from all and summarize? But to hand it off end to end? I haven't seen anyone accomplish this.
        • hoppp 1 hour ago
          But they don't respond with fear and flailing arms!
  • csiegert 30 minutes ago
    Is Deno affected, too? It uses brotli by default. But I don’t know how it is implemented.
    • gnabgib 28 minutes ago
      Deno is dead (baby)

      > We will support the Deno runtime for another year with monthly releases containing bug fixes and security updates. After that year we will end our development

      https://deno.com/blog/cloudflare

      • csiegert 6 minutes ago
        I know that it is dead but since they provide security updates for another year I haven’t migrated off of it immediately. Anyways, the Deno runtime uses a brotli Rust crate that does not wrap C code, and with unsafe off, so I assume it is safe.
        • gnabgib 3 minutes ago
          So a person of rhetorical questions? Great
    • Amsozzer 19 minutes ago
      I doubt it
  • cowlevel 3 hours ago
    Likely mitigation: disable brotli (br) content-encoding on both sides
    • thayne 1 hour ago
      Unfortunately, AFAICT, there is no way to do this for node's fetch. I suspect there are other client libraries that don't have a way to disable it.
  • dboreham 1 hour ago
    This is a better article: https://www.aikido.dev/blog/python-packages-vulnerable-node2...

    and this is the actual CVE report, which doesn't say much: https://www.cve.org/CVERecord?id=CVE-2026-111497

  • cpburns2009 1 hour ago
  • QuadmasterXLII 2 hours ago
    is flask hello world with gunicorn behind apache vulnerable?
    • cpburns2009 1 hour ago
      Only decompression with Google's brotli library is affected. So if you use "Brotli" or "brotlicffi" in your Python app to decompress brotli, you're vulnerable. Compressing responses with brotli from Apache is safe.
    • TZubiri 2 hours ago
      what I can say is that a 5 liner hello world starting with ‘import socket’ is not affected

      whether a hello wolrd in fastapi is affected might also be interesting

  • bogomind 2 hours ago
    [flagged]
  • bibekadhikari 2 hours ago
    Worth checking how brotli actually reaches your stack. In Node it's bundled into the runtime itself (zlib's brotli support), so an audit of your package tree won't surface it the way a normal dependency would - the fix arrives with a runtime release, not a package bump. The Python package on PyPI is already at 1.2.1. Until your runtime picks up the patched brotli, refusing br content-encoding at the edge seems like the fastest mitigation.
    • thayne 1 hour ago
      > refusing br content-encoding at the edge seems like the fastest mitigation.

      That's pretty difficult if you make outbound requests, and don't already have a TLS interception proxy set up.

    • cowlevel 1 hour ago
      This is an AI karmabot comment, it should remain flagged
  • DogeGode 2 hours ago
    Another day, another buffer-overflow vulnerability in C code …
  • profdevloper 2 hours ago
  • userbinator 34 minutes ago
    Brotli, another one of those pseudostandards[1] from Big G that I was avoiding all along. Dodged another bullet.

    [1] When more than half of the "standard" https://www.rfc-editor.org/info/rfc7932/#page-44 is an opaque binary blob, they're really not encouraging independent implementations.