CVE-2026-33762
LOWCVE-2026-33762 is a low-severity (CVSS 2.8) CWE-129 vulnerability in github.com/go-git/go-git/v5. O3 Security confirms whether CVE-2026-33762 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
go-git: Missing validation decoding Index v4 files leads to panic
Blast Radius
github.com/go-git/go-git/v5Real-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
go-git is an extensible git implementation library written in pure Go. Prior to version 5.17.1, go-git’s index decoder for format version 4 fails to validate the path name prefix length before applying it to the previously decoded path name. A maliciously crafted index file can trigger an out-of-bounds slice operation, resulting in a runtime panic during normal index parsing. This issue only affects Git index format version 4. Earlier formats (go-git supports only v2 and v3) are not vulnerable to this issue. This issue has been patched in version 5.17.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/go-git/go-git/v5 | all versions | 5.17.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/go-git/go-git/v5. 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 github.com/go-git/go-git/v5 to 5.17.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33762 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-2026-33762 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-2026-33762. 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-2026-33762 in your dependencies?
O3 detects CVE-2026-33762 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.