CVE-2026-4428
CVE-2026-4428 is a CWE-299 vulnerability in aws-lc-fips-sys. O3 Security confirms whether CVE-2026-4428 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
CRL Distribution Point Scope Check Logic Error in AWS-LC
Real-World Exposure
aws-lc-fips-sys🦀aws-lc-sysReal-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
A logic error in CRL distribution point validation in AWS-LC before 1.71.0 causes partitioned CRLs to be incorrectly rejected as out of scope, which allows a revoked certificate to bypass certificate revocation checks.
To remediate this issue, users should upgrade to AWS-LC 1.71.0 or AWS-LC-FIPS-3.3.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | aws-lc-fips-sys | ≥ 0.13.0&&< 0.13.13 | 0.13.13 |
| 🦀crates.io | aws-lc-sys | ≥ 0.15.0&&< 0.39.0 | 0.39.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aws-lc-fips-sys. 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 aws-lc-fips-sys to 0.13.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-4428 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-2026-4428 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-2026-4428. 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-2026-4428 in your dependencies?
O3 detects CVE-2026-4428 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.