GHSA-8gq9-2x98-w8hf
HIGHprotobuf-cpp and protobuf-python have 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🐍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
A message parsing and memory management vulnerability in ProtocolBuffer’s C++ and Python implementations can trigger an out of memory (OOM) failure when processing a specially crafted message, which could lead to a denial of service (DoS) on services using the libraries.
Reporter: ClusterFuzz
Affected versions: All versions of C++ Protobufs (including Python) prior to the versions listed below.
Severity & Impact
As scored by google
Medium 5.7 - CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Asscored byt NIST
High 7.5 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
A small (~500 KB) malicious payload can be constructed which causes the running service to allocate more than 3GB of RAM.
Proof of Concept
For reproduction details, please refer to the unit test that identifies the specific inputs that exercise this parsing weakness.
Mitigation / Patching
Please update to the latest available versions of the following packages:
- protobuf-cpp (3.18.3, 3.19.5, 3.20.2, 3.21.6)
- protobuf-python (3.18.3, 3.19.5, 3.20.2, 4.21.6)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | protobuf | all versions | 3.18.3 |
| 🐍PyPI | protobuf | ≥ 3.19.0&&< 3.19.5 | 3.19.5 |
| 🐍PyPI | protobuf | ≥ 3.20.0&&< 3.20.2 | 3.20.2 |
| 🐍PyPI | protobuf | ≥ 4.0.0&&< 4.21.6 | 4.21.6 |
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 3.18.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8gq9-2x98-w8hf 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-8gq9-2x98-w8hf 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-8gq9-2x98-w8hf. 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-8gq9-2x98-w8hf in your dependencies?
O3 detects GHSA-8gq9-2x98-w8hf across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.