Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)GHSA-rrx3-2x4g-mq2h
HIGHFix: bugsink/bugsink@1201f75GHSA-rrx3-2x4g-mq2h is a high-severity (CVSS 7.5) CWE-770 vulnerability in bugsink. A fix is available for bugsink — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rrx3-2x4g-mq2h.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
bugsinkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
In affected versions, a specially crafted Brotli-compressed envelope can cause Bugsink to spend excessive CPU time in decompression, leading to denial of service.
This can be done if the DSN is known, which it is in many common setups (JavaScript, Mobile Apps).
Patches
Patched in Bugsink 2.0.6
References
The vulnerability in this security advisory is similar to, but distinct from, another brotli-related problem in Bugsink:
https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | bugsink | all versions | 2.0.6pip install --upgrade 'bugsink==2.0.6' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for bugsink, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update bugsink to 2.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rrx3-2x4g-mq2h is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is GHSA-rrx3-2x4g-mq2h in your dependencies?
Find it across PyPI, including transitive dependencies.