GHSA-8qvm-5x2c-j2w7
protobuf-python has a potential Denial of Service issue
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
protobuf🐍protobuf🐍protobufReal-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
Summary
Any project that uses Protobuf pure-Python backend to parse untrusted Protocol Buffers data containing an arbitrary number of recursive groups, recursive messages or a series of SGROUP tags can be corrupted by exceeding the Python recursion limit.
Reporter: Alexis Challande, Trail of Bits Ecosystem Security Team [email protected]
Affected versions: This issue only affects the pure-Python implementation of protobuf-python backend. This is the implementation when PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python environment variable is set or the default when protobuf is used from Bazel or pure-Python PyPi wheels. CPython PyPi wheels do not use pure-Python by default.
This is a Python variant of a previous issue affecting protobuf-java.
Severity
This is a potential Denial of Service. Parsing nested protobuf data creates unbounded recursions that can be abused by an attacker.
Proof of Concept
For reproduction details, please refer to the unit tests decoder_test.py and message_test
Remediation and Mitigation
A mitigation is available now. Please update to the latest available versions of the following packages:
- protobuf-python(4.25.8, 5.29.5, 6.31.1)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | protobuf | all versions | 4.25.8 |
| 🐍PyPI | protobuf | ≥ 5.26.0rc1&&< 5.29.5 | 5.29.5 |
| 🐍PyPI | protobuf | ≥ 6.30.0rc1&&< 6.31.1 | 6.31.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for protobuf. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update protobuf to 4.25.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8qvm-5x2c-j2w7 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-8qvm-5x2c-j2w7 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-8qvm-5x2c-j2w7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8qvm-5x2c-j2w7 in your dependencies?
O3 detects GHSA-8qvm-5x2c-j2w7 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.