CVE-2026-41898
CVE-2026-41898 is a remote code execution vulnerability in openssl. O3 Security confirms whether CVE-2026-41898 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
rust-openssl: Unchecked callback-returned length in PSK and cookie generate trampolines can cause OpenSSL to leak adjacent memory to the network peer
Blast Radius
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 0.9.24 to before 0.10.78, the FFI trampolines behind SslContextBuilder::set_psk_client_callback, set_psk_server_callback, set_cookie_generate_cb, and set_stateless_cookie_generate_cb forwarded the user closure's returned usize directly to OpenSSL without checking it against the &mut [u8] that was handed to the closure. This can lead to buffer overflows and other unintended consequences. This vulnerability is fixed in 0.10.78.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | openssl | ≥ 0.9.24&&< 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-2026-41898 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-2026-41898 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-2026-41898. 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-2026-41898 in your dependencies?
O3 detects CVE-2026-41898 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.