CVE-2026-23965
Published: 22 January 2026
Summary
CVE-2026-23965 is a high-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Juneandgreen Sm-Crypto. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 1.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.
Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.
PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.
Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.
Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.
Integrity tools commonly rely on cryptographic signatures whose improper validation this weakness covers.
Authenticity validation commonly relies on cryptographic signature or certificate checks that this control enforces.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated signature forgery in a cryptographic library directly enables exploitation of public-facing applications relying on SM2 signature verification for auth/integrity.
NVD Description
sm-crypto provides JavaScript implementations of the Chinese cryptographic algorithms SM2, SM3, and SM4. A signature forgery vulnerability exists in the SM2 signature verification logic of sm-crypto prior to version 0.4.0. Under default configurations, an attacker can forge valid signatures for…
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arbitrary public keys. If the message space contains sufficient redundancy, the attacker can fix the prefix of the message associated with the forged signature to satisfy specific formatting requirements. Version 0.4.0 patches the issue.
Deeper analysisAI
CVE-2026-23965 is a signature forgery vulnerability in the SM2 signature verification logic of the sm-crypto JavaScript library, which provides implementations of the Chinese cryptographic algorithms SM2, SM3, and SM4. The flaw affects versions of sm-crypto prior to 0.4.0 and is classified under CWE-347. It was published on 2026-01-22 with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N), highlighting high integrity impact.
Remote attackers require no privileges or user interaction to exploit the vulnerability under default configurations. They can forge valid SM2 signatures for arbitrary public keys, potentially bypassing authentication or integrity checks in applications relying on the library. If the message space contains sufficient redundancy, attackers can fix the prefix of the associated message to satisfy specific formatting requirements, enabling targeted forgery.
The issue is patched in sm-crypto version 0.4.0. Security practitioners should upgrade to this version immediately. Further details, including the patch commit, are available at https://github.com/JuneAndGreen/sm-crypto/commit/85295a859d0766222d12ce2be3e6fce7b438b510, and the GitHub security advisory at https://github.com/JuneAndGreen/sm-crypto/security/advisories/GHSA-hpwg-xg7m-3p6m.
Details
- CWE(s)