CVE-2026-22698
RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
sm2Real-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
RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k and decrypt any ciphertext given only the public key and ciphertext. This issue has been patched via commit e4f7778.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | sm2 | ≥ 0.14.0-pre.0 | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sm2. 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.
Remediation status
No patched version of sm2 has shipped for CVE-2026-22698 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-22698 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-2026-22698. 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-2026-22698 in your dependencies?
O3 detects CVE-2026-22698 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.