GHSA-f8m3-jpxr-hm5x is a high-severity (CVSS 7.8) Out-of-bounds Write vulnerability in bsdiff4. O3 Security confirms whether GHSA-f8m3-jpxr-hm5x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
bsdiff4 out-of-bounds write via patch file
Real-World Exposure
bsdiff4Real-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 buffer overflow in the patching routine of bsdiff4 before 1.2.0 allows an attacker to write to heap memory (beyond allocated bounds) via a crafted patch file.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | bsdiff4 | all versions | 1.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for bsdiff4. 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 bsdiff4 to 1.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f8m3-jpxr-hm5x 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-f8m3-jpxr-hm5x 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-f8m3-jpxr-hm5x. 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-f8m3-jpxr-hm5x in your dependencies?
O3 detects GHSA-f8m3-jpxr-hm5x across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.