CVE-2026-23966 is a critical-severity (CVSS 9.1) CWE-345 vulnerability in sm-crypto. A fix is available for sm-crypto — see the affected versions and patch details below.
sm-crypto Affected by Private Key Recovery in SM2-PKE
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-23966.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
sm-cryptonpmDescription
sm-crypto provides JavaScript implementations of the Chinese cryptographic algorithms SM2, SM3, and SM4. A private key recovery vulnerability exists in the SM2 decryption logic of sm-crypto prior to version 0.3.14. By interacting with the SM2 decryption interface multiple times, an attacker can fully recover the private key within approximately several hundred interactions. Version 0.3.14 patches the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | sm-crypto | all versions | 0.3.14npm install sm-crypto@0.3.14 |
Affected Products
sm-cryptojuneandgreenDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sm-crypto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update sm-crypto to 0.3.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23966 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.
Frequently Asked Questions
Is CVE-2026-23966 in your dependencies?
Find it across npm, including transitive dependencies.