Forge: RSA PKCS#1 v1.5 signature forgery via non-canonical DigestInfo encoding

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

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary RSASSA-PKCS1-v1_5 signature verification (`publicKey.verify()` with the default scheme, also used by X.509 certificate and PKCS#7 verification) accepted non-canonical BER encodings of the DigestInfo, such as NULL parameters with content and non-minimal lengths. These leave attacker-controlled bytes inside an accepted DigestInfo, which allows signatures to be forged without the private key for RSA keys with a low public exponent (e=3). Fixed in node-forge 1.4.1.

Details In `lib/rsa.js`, `key.verify()` with the default `RSASSA-PKCS1-V1_5` scheme removes the padding, parses the recovered DigestInfo with the lenient BER parser `asn1.fromDer()` and checks its structure with `asn1.validate()` against `digestInfoValidator`. Neither requires a canonical DER encoding, so verification accepted, among others: - NULL parameters with content bytes (e.g. `05 40 `) - non-NULL or constructed values in the parameters position - non-minimal (long form) and indefinite lengths -…

Published by the source

10 Nov 2026, 15:57 UTC

Last modified by the source

10 Nov 2026, 16:15 UTC

Source last checked

11 Nov 2026, 06:00 UTC

1. Revision 2 · amended · 11 Nov 2026

   Amended from osv record GHSA-6qrw-m8cv-hcxf

2. Revision 1 · created · 10 Nov 2026

   Published from ghsa record GHSA-6qrw-m8cv-hcxf

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# Patch Next advisory brief: CVE-2026-119192

Advisory: Forge: RSA PKCS#1 v1.5 signature forgery via non-canonical DigestInfo encoding
IDs: CVE-2026-119192, GHSA-6qrw-m8cv-hcxf
Record: https://patchnext.com/advisories/cve-2026-119192 (revision 2, source checked 11 Nov 2026, 06:00 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: node-forge 1.4.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm node-forge: affected < 1.4.1; fixed in 1.4.1

## Suggested inspection (read-only)
- `npm ls node-forge --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 node-forge.
- 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://github.com/advisories/GHSA-6qrw-m8cv-hcxf (GitHub-reviewed advisory GHSA-6qrw-m8cv-hcxf lists affected ranges: npm node-forge >=0 <=1.4.0)
- Verified: https://osv.dev/vulnerability/GHSA-6qrw-m8cv-hcxf (OSV record GHSA-6qrw-m8cv-hcxf lists affected ranges: npm node-forge >=0 <1.4.1 (fixed))

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