CVE-2026-24850 is a medium-severity (CVSS 5.3) CWE-347 vulnerability in ml-dsa. O3 Security confirms whether CVE-2026-24850 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
ML-DSA Signature Verification Accepts Signatures with Repeated Hint Indices
Real-World Exposure
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
The ML-DSA crate is a Rust implementation of the Module-Lattice-Based Digital Signature Standard (ML-DSA). Starting in version 0.0.4 and prior to version 0.1.0-rc.4, the ML-DSA signature verification implementation in the RustCrypto ml-dsa crate incorrectly accepts signatures with repeated (duplicate) hint indices. According to the ML-DSA specification (FIPS 204 / RFC 9881), hint indices within each polynomial must be strictly increasing. The current implementation uses a non-strict monotonic check (<= instead of <), allowing duplicate indices. This is a regression bug. The original implementation was correct, but a commit in version 0.0.4 inadvertently changed the strict < comparison to <=, introducing the vulnerability. Version 0.1.0-rc.4 fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | ml-dsa | ≥ 0.0.4&&< 0.1.0-rc.4 | 0.1.0-rc.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for 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 ml-dsa to 0.1.0-rc.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-24850 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-2026-24850 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-2026-24850. 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-2026-24850 in your dependencies?
O3 detects CVE-2026-24850 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.