sm-crypto Affected by Signature Forgery in SM2-DSA

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-23965: 0.21% estimated exploitation activity in the next 30 days; percentile 11.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A signature forgery vulnerability exists in the SM2 signature verification logic of sm-crypto. Under default configurations, an attacker can forge valid signatures for 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. Credit This vulnerability was discovered by: - XlabAI Team of Tencent Xuanwu Lab - Atuin Automated Vulnerability Discovery Engine

Published by the source

21 Jan 2026, 16:13 UTC

Last modified by the source

3 Feb 2026, 03:10 UTC

Source last checked

26 Oct 2026, 12:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hpwg-xg7m-3p6m

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hpwg-xg7m-3p6m

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# Patch Next advisory brief: CVE-2026-23965

Advisory: sm-crypto Affected by Signature Forgery in SM2-DSA
IDs: CVE-2026-23965, GHSA-hpwg-xg7m-3p6m
Record: https://patchnext.com/advisories/cve-2026-23965 (revision 2, source checked 26 Oct 2026, 12:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sm-crypto 0.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm sm-crypto: affected < 0.4.0; fixed in 0.4.0

## Suggested inspection (read-only)
- `npm ls sm-crypto --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sm-crypto.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-hpwg-xg7m-3p6m (OSV record GHSA-hpwg-xg7m-3p6m lists affected ranges: npm sm-crypto >=0 <0.4.0 (fixed))
- Verified: https://github.com/advisories/GHSA-hpwg-xg7m-3p6m (GitHub-reviewed advisory GHSA-hpwg-xg7m-3p6m lists affected ranges: npm sm-crypto >=0 <0.4.0)

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