CVE-2026-22700 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in sm2. No vendor fix is recorded yet; mitigation options are listed below.
RustCrypto Has Insufficient Length Validation in decrypt() in SM2-PKE
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-22700.
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.
How urgent is this, really
CVE-2026-22700 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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 denial-of-service vulnerability exists in the SM2 public-key encryption (PKE) implementation: the decrypt() path performs unchecked slice::split_at operations on input buffers derived from untrusted ciphertext. An attacker can submit short/undersized ciphertext or carefully-crafted DER-encoded structures to trigger bounds-check panics (Rust unwinding) which crash the calling thread or process. This issue has been patched via commit e60e991.
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of sm2 has shipped for CVE-2026-22700 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-22700 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-22700. 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-2026-22700 in your dependencies?
O3 Security finds CVE-2026-22700 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.