CVE-2026-23967Network attack vector

Integrity-control bypass via malleable SM2 signatures

Published Jan 22, 2026 · Updated Jan 22, 2026

Signature malleability in JuneAndGreen sm-crypto before 0.3.14 allows remote attackers to derive a new valid signature for a signed message. The SM2 doVerifySignature path accepts a derived variant of an existing signature for the same message; the precise missing validation remains unpublished. Possession of a valid message-signature pair is required, and the flaw defeats integrity controls that treat each signature representation as unique without enabling signatures for new messages.

CVSS severity7.5
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Signature malleability in JuneAndGreen sm-crypto before 0.3.14 allows remote attackers to derive a new valid signature for a signed message. The SM2 doVerifySignature path accepts a derived variant of an existing signature for the same message; the precise missing validation remains unpublished. Possession of a valid message-signature pair is required, and the flaw defeats integrity controls that treat each signature representation as unique without enabling signatures for new messages.

The record

CVE
CVE-2026-23967
Published
Jan 22, 2026
Updated
Jan 22, 2026
Vendor
JuneAndGreen
Product
sm-crypto
Classifications
CWE-347, T1553
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.3.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

JuneAndGreen · sm-cryptoversion=< 0.3.14

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
T1553Subvert Trust Controls

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo