HighFix available
joserfc — security advisory
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.
- Products
- joserfc
- Affected versions
- 1.1.0-1, 1.2.0-1, 1.2.2-1, 1.3.1-1, 1.3.2-1, 1.3.4-1, 1.4.0-1, 1.4.1-1, 1.4.3-1, 1.5.0-1, 1.6.0-1, 1.6.1-1, 1.6.2-1, 1.6.3-1, 1.6.4-1, 1.6.5-1, 1.6.8-1, 1.7.0-1, 1.7.1-1, 1.7.2-1, 1.7.3-1, 1.7.4-1, 1.7.5-1
- Fixed versions
- 1.6.8-1
- CVEs
- CVE-2026-49852
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 09:56 UTC · Revision 2
Source evidence
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.
osv:DEBIAN-CVE-2026-49852
joserfc
Fixed versions: Not specified
joserfc
Fixed versions: 1.6.8-1
Complete source record
{
"id": "f0b95e6ac486042b05fb29635984279edf080c66d6d67cadc663d85bd831269b",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-49852",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-49852",
"summary": "joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.6.8, joserfc.jwt.decode accepts attacker-forged HMAC-signed tokens when the caller-supplied verification key is the empty string or None, because HMACAlgorithm.sign and HMACAlgorithm.verify in src/joserfc/_rfc7518/jws_algs.py pass the output of OctKey.get_op_key(...) to hmac.new(...) and OctKey.import_key in src/joserfc/_rfc7518/oct_key.py only emits a SecurityWarning for keys shorter than 14 bytes without rejecting zero-length input. This issue is fixed in version 1.6.8.",
"evidence": "osv:DEBIAN-CVE-2026-49852",
"products": [
{
"name": {
"value": "joserfc",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.1.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.2.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.2.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.3.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.3.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.3.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.5.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.6.8-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.7.5-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "joserfc",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.6.8-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "1.1.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.2.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.2.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.3.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.3.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.3.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.4.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.4.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.4.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.6.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.6.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.6.2-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.6.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.6.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "1.6.5-1",
"evidence": "/affected/1/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-49852",
"aliases": [
"DEBIAN-CVE-2026-49852"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "joserfc",
"purl": "pkg:deb/debian/joserfc?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.1.0-1",
"1.2.0-1",
"1.2.2-1",
"1.3.1-1",
"1.3.2-1",
"1.3.4-1",
"1.4.0-1",
"1.4.1-1",
"1.4.3-1",
"1.5.0-1",
"1.6.0-1",
"1.6.1-1",
"1.6.2-1",
"1.6.3-1",
"1.6.4-1",
"1.6.5-1",
"1.6.8-1",
"1.7.0-1",
"1.7.1-1",
"1.7.2-1",
"1.7.3-1",
"1.7.4-1",
"1.7.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49852.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.6.8-1"
}
]
}
],
"package": {
"name": "joserfc",
"purl": "pkg:deb/debian/joserfc?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.1.0-1",
"1.2.0-1",
"1.2.2-1",
"1.3.1-1",
"1.3.2-1",
"1.3.4-1",
"1.4.0-1",
"1.4.1-1",
"1.4.3-1",
"1.5.0-1",
"1.6.0-1",
"1.6.1-1",
"1.6.2-1",
"1.6.3-1",
"1.6.4-1",
"1.6.5-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49852.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-25T10:00:36.901373730Z",
"provider": "osv",
"upstream": [
"CVE-2026-49852"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-49852"
]
},
"related_cves": [
{
"value": "CVE-2026-49852",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 445364,
"published_at": "2026-07-17T20:17:23.27+00:00"
}