CVE-2022-1941
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
A parsing vulnerability for the MessageSet type in the ProtocolBuffers versions prior to and including 3.16.1, 3.17.3, 3.18.2, 3.19.4, 3.20.1 and 3.21.5 for protobuf-cpp, and versions prior to and including 3.16.1, 3.17.3, 3.18.2, 3.19.4, 3.20.1 and 4.21.5 for protobuf-python can lead to out of memory failures. A specially crafted message with multiple key-value per elements creates parsing issues, and can lead to a Denial of Service against services receiving unsanitized input. We recommend upgrading to versions 3.18.3, 3.19.5, 3.20.2, 3.21.6 for protobuf-cpp and 3.18.3, 3.19.5, 3.20.2, 4.21.6 for protobuf-python. Versions for 3.16 and 3.17 are no longer updated.
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 CVE-2022-1941 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 CVE-2022-1941 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 CVE-2022-1941. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-1941 in your dependencies?
O3 detects CVE-2022-1941 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.