GHSA-xrf2-5r3p-5wgj
libcrux: Panic in Signature Hint Decoding During Verification
Blast Radius
libcrux-ml-dsaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
During ML-DSA verification the serialized hint values are decoded as specified in algorithm 22 HintBitUnpack of FIPS 204, subsection 7.1. The algorithm requires that the cumulative hint counters per row of the hint vector are strictly increasing and below a maximum value which depends on the choice of ML-DSA parameter set (line 4).
In libcrux-ml-dsa, hint decoding did not check the boundedness of the cumulative hint counter of the last row of the hint vector.
Impact
A manipulated invalid hint can cause an out-of-bounds memory access since the hint decoding logic may attempt to read outside the bounds of the serialized signature, causing a runtime panic.
Mitigation
Starting from version 0.0.8, hint decoding will check the cumulative hint counter of the last row as well.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | libcrux-ml-dsa | all versions | 0.0.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for libcrux-ml-dsa. 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 libcrux-ml-dsa to 0.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xrf2-5r3p-5wgj 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-xrf2-5r3p-5wgj 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-xrf2-5r3p-5wgj. 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-xrf2-5r3p-5wgj in your dependencies?
O3 detects GHSA-xrf2-5r3p-5wgj across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.