CVE-2026-41681
Fix: rust-openssl/rust-openssl@826c388CVE-2026-41681 is a CWE-121 vulnerability in openssl. O3 Security confirms whether CVE-2026-41681 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
rust-openssl: MdCtxRef::digest_final() writes past caller buffer with no length check
Real-World Exposure
opensslReal-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
rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.10.39 to before 0.10.78, EVP_DigestFinal() always writes EVP_MD_CTX_size(ctx) to the out buffer. If out is smaller than that, MdCtxRef::digest_final() writes past its end, usually corrupting the stack. This is reachable from safe Rust. This vulnerability is fixed in 0.10.78.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | openssl | ≥ 0.10.39&&< 0.10.78 | 0.10.78 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssl. 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 openssl to 0.10.78 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41681 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-2026-41681 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-2026-41681. 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-2026-41681 in your dependencies?
O3 detects CVE-2026-41681 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.