DEBIAN-CVE-2026-44699
LibJWT is a C JSON Web Token Library. From 3.0.0 to 3.3.2, libjwt accepts an RSA JWK that does not contain an alg parameter as the verification key for an HS256/HS384/HS512 token. In the OpenSSL backend, this causes HMAC verification to run with a zero-length key, so an attacker can forge a valid JWT without knowing any secret or RSA private key. This is an algorithm-confusion authentication bypass. It affects applications that load RSA keys from JWKS where alg is omitted, which is valid JWK syntax and common in real deployments, and then choose the verification algorithm from the JWT header, for example in a kid lookup callback. This vulnerability is fixed in 3.3.3.
DEBIAN-CVE-2026-44699
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:DEBIAN-CVE-2026-44699
libjwt3
Source reference: /affected/0/package/name
- Affected versions
- 3.2.2-1
Source reference:
/affected/0/versions3.2.3-1Source reference:
/affected/0/versions3.3.2-1Source reference:
/affected/0/versions - Fixed versions
- 3.3.3-1
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": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.3.3-1"
}
]
}
],
"package": {
"name": "libjwt3",
"purl": "pkg:deb/debian/libjwt3?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.2.2-1",
"3.2.3-1",
"3.3.2-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44699.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57704 · Revision 1
- Added to Heist Feed
- Publisher date