GHSA-8r3f-844c-mc37
HIGHGHSA-8r3f-844c-mc37 is a high-severity (CVSS 7.5) vulnerability in google.golang.org/protobuf. O3 Security confirms whether GHSA-8r3f-844c-mc37 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Golang protojson.Unmarshal function infinite loop when unmarshaling certain forms of invalid JSON
Blast Radius
google.golang.org/protobuf🐹google.golang.org/protobuf/encoding/protojson🐹google.golang.org/protobuf/internal/encoding/jsonReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
The protojson.Unmarshal function can enter an infinite loop when unmarshaling certain forms of invalid JSON. This condition can occur when unmarshaling into a message which contains a google.protobuf.Any value, or when the UnmarshalOptions.DiscardUnknown option is set.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | google.golang.org/protobuf | all versions | 1.33.0 |
| 🐹Go | google.golang.org/protobuf/encoding/protojson | all versions | 1.33.0 |
| 🐹Go | google.golang.org/protobuf/internal/encoding/json | all versions | 1.33.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for google.golang.org/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 google.golang.org/protobuf to 1.33.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8r3f-844c-mc37 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-8r3f-844c-mc37 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-8r3f-844c-mc37. 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-8r3f-844c-mc37 in your dependencies?
O3 detects GHSA-8r3f-844c-mc37 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.