Forge has signature forgery in RSA-PKCS due to ASN.1 extra field
## Summary RSASSA PKCS#1 v1.5 signature verification accepts forged signatures for low public exponent keys (e=3). Attackers can forge signatures by stuffing “garbage” bytes within the ASN structure in order to construct a signature that passes verification, enabling [Bleichenbacher style forgery](https://mailarchive.ietf.org/arch/msg/openpgp/5rnE9ZRN1AokBVj3VqblGlP63QE/). This issue is similar to [CVE-2022-24771](https://github.com/digitalbazaar/forge/security/advisories/GHSA-cfm4-qjh2-4765), but adds bytes in an addition field within the ASN structure, rather than outside of it. Additionally, forge does not validate that signatures include a minimum of 8 bytes of padding as [defined by the specification](https://datatracker.ietf.org/doc/html/rfc2313#section-8), providing attackers additional space to construct Bleichenbacher forgeries. ## Impacted Deployments **Tested commit:** `8e1d527fe8ec2670499068db783172d4fb9012e5` **Affected versions:** tested on v1.3.3 (latest release) and recent prior versions. **Configuration assumptions:** - Invoke key.verify with defaults (default `scheme` uses RSASSA-PKCS1-v1_5). - `_parseAllDigestBytes: true` (default setting). ## Root Cause In `lib/rsa.js`, `key.verify(...)`, forge decrypts the signature block, decodes PKCS#1 v1.5 padding (`_decodePkcs1_v1_5`), parses ASN.1, and compares `capture.digest` to the provided digest. Two issues are present with this logic: 1. Strict DER byte-consumption (`_parseAllDigestBytes`) only guarantees all b
GHSA-ppp5-5v6c-4jwp
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-ppp5-5v6c-4jwp
node-forge
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.4.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.4.0"
}
]
}
],
"package": {
"name": "node-forge",
"purl": "pkg:npm/node-forge",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-ppp5-5v6c-4jwp/GHSA-ppp5-5v6c-4jwp.json"
}
}
]- Related CVEs
- CVE-2026-33894
Source reference:
/aliasesCVE-2026-85393Source reference:
/aliases
Publisher severity
high
Source reference: /database_specific/severity
- Event
- #63997 · Revision 1
- Added to Heist Feed
- Publisher date