Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
node-forge versions through 1.4.0 are affected: during RSA PKCS#1 v1.5 signature verification, the library does not check the element count of nested DigestAlgorithm sequences. An attacker can place extra bytes inside that sequence to forge signatures for arbitrary messages when low-exponent RSA keys are used, and the source describes this as an incomplete fix for CVE-2026-33894. The source gives no fixed version and no specific mitigation advice.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.7 | High | 4.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N | CNA (VulnCheck) |
- CISA KEV Not listed.
- EPSS 0.0048, the 41st percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 13:34 UTC First seen by agentprime
- 31 Oct 2026, 13:34 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-86w9-cpqp-85rv
- OSV: GHSA-86w9-cpqp-85rv
- nvd.nist.gov/vuln/detail/CVE-2026-85393
- github.com/digitalbazaar/forge/issues/1149
- github.com/digitalbazaar/forge/pull/1152
- github.com/advisories/GHSA-ppp5-5v6c-4jwp
- github.com/digitalbazaar/forge
- github.com/digitalbazaar/forge/blob/v1.4.0/lib/asn1.js
- github.com/digitalbazaar/forge/blob/v1.4.0/lib/rsa.js
- www.vulncheck.com/advisories/node-forge-through-1.4.0-rsa-pkcs-1-1.5-signature-forgery-via-nested-digestalgorithm-padding