Security readout for executives and security teams
Plain-English summary
CVE-2026-23966 affects sm-crypto, a JavaScript cryptography library. In versions before 0.3.14, repeated interaction with the SM2 decryption function can let an attacker recover the private key. This is business-critical where sm-crypto protects sensitive data, identity, payments, or regulated communications.
Executive priority
Treat as urgent for any externally reachable service using sm-crypto SM2 decryption. Compromise of a private key can undermine confidentiality and trust beyond one request or session. Patch and assess key exposure promptly.
Technical view
The issue is in sm-crypto SM2-PKE decryption logic before 0.3.14. The advisory describes full private-key recovery after approximately several hundred interactions with the decryption interface. CVSS is 9.1, network exploitable, low complexity, no privileges or user interaction. Fixed version is 0.3.14.
Likely exposure
Exposure is most likely in Node.js or browser JavaScript applications that depend on JuneAndGreen sm-crypto before 0.3.14 and expose SM2 decryption to untrusted input or remote callers.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. The published advisory states an attacker can recover the private key by interacting with the SM2 decryption interface multiple times.
Researcher notes
Evidence is limited to the CVE record, GitHub advisory, and patch commit. Avoid assuming all sm-crypto uses are exploitable; the relevant condition is vulnerable SM2 decryption exposed to attacker-controlled interactions.
Mitigation direction
- Upgrade sm-crypto to version 0.3.14 or later.
- Inventory applications and transitive dependencies using sm-crypto.
- Prioritize systems exposing SM2 decryption to remote or untrusted inputs.
- After patching, assess whether exposed SM2 private keys should be replaced.
- Check vendor advisory for any updated guidance.
Validation and detection
- Review package.json and lockfiles for sm-crypto versions below 0.3.14.
- Use software composition analysis to find direct and transitive usage.
- Confirm production deployments run the patched dependency version.
- Identify endpoints or workflows invoking SM2 decryption.
- Review logs for unusual repeated decryption requests, if available.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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Open ATT&CK lookupCVE-2026-23966 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/JuneAndGreen/sm-crypto/security/advisories/GHSA-pgx9-497m-6c4vCVE reference · x_refsource_CONFIRM
- https://github.com/JuneAndGreen/sm-crypto/commit/b1c824e58fdf1eaa73692c124a095819a8c45707CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Insufficient Verification of Data Authenticity
Insufficient Verification of Data Authenticity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.