UnratedFix available

DEBIAN-CVE-2026-48522

Type: advisorySource: OSV1 source record

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient passes its uri argument directly to urllib.request.urlopen() which uses Python stdlib's default OpenerDirector registering HTTPHandler, HTTPSHandler, FTPHandler, FileHandler, and DataHandler. There is currently no documented option to restrict which schemes PyJWKClient will fetch. If an application's jku URL ingestion path accepts attacker-influenced URLs (e.g., from JWT header, configuration file, OAuth flow parameter), the attacker can cause PyJWKClient to read arbitrary local files via file:// (SSRF on local filesystem), cause PyJWKClient to attempt FTP / data-URI fetches (broader SSRF surface), or forge tokens that PyJWT verifies as valid. The library does not directly return non-HTTP(S) URI contents to the attacker; the chained "plant a JWKS to forge tokens" scenario described in the original report requires additional application-layer flaws (attacker write access to a filesystem path, untrusted jku derivation) that this fix does not address. This vulnerability is fixed in 2.13.0.

Announced 28 May 2026Source revision 1

Original source ↗

DEBIAN-CVE-2026-48522

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-2026-48522

pyjwt

Source reference: /affected/0/package/name

Affected versions: 2.10.1-1
Source reference: /affected/0/versions
2.10.1-2
Source reference: /affected/0/versions
2.10.1-3
Source reference: /affected/0/versions
2.10.1-4
Source reference: /affected/0/versions
2.11.0-2
Source reference: /affected/0/versions
2.12.1-1
Source reference: /affected/0/versions
2.13.0-1
Source reference: /affected/0/versions
2.14.0-1
Source reference: /affected/0/versions
2.15.0-1
Source reference: /affected/0/versions
2.15.1-1
Source reference: /affected/0/versions
2.6.0-1
Source reference: /affected/0/versions
2.6.0-1+deb12u1
Source reference: /affected/0/versions
2.7.0-1
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

pyjwt

Source reference: /affected/1/package/name

Affected versions: 2.10.1-2
Source reference: /affected/1/versions
2.10.1-2+deb13u1
Source reference: /affected/1/versions
2.10.1-3
Source reference: /affected/1/versions
2.10.1-4
Source reference: /affected/1/versions
2.11.0-2
Source reference: /affected/1/versions
2.12.1-1
Source reference: /affected/1/versions
2.13.0-1
Source reference: /affected/1/versions
2.14.0-1
Source reference: /affected/1/versions
2.15.0-1
Source reference: /affected/1/versions
2.15.1-1
Source reference: /affected/1/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

pyjwt

Source reference: /affected/2/package/name

Affected versions: 2.10.1-2
Source reference: /affected/2/versions
2.10.1-3
Source reference: /affected/2/versions
2.10.1-4
Source reference: /affected/2/versions
2.11.0-2
Source reference: /affected/2/versions
2.12.1-1
Source reference: /affected/2/versions
Fixed versions: 2.13.0-1
Source reference: /affected/2/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"
          }
        ]
      }
    ],
    "package": {
      "name": "pyjwt",
      "purl": "pkg:deb/debian/pyjwt?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "2.10.1-1",
      "2.10.1-2",
      "2.10.1-3",
      "2.10.1-4",
      "2.11.0-2",
      "2.12.1-1",
      "2.13.0-1",
      "2.14.0-1",
      "2.15.0-1",
      "2.15.1-1",
      "2.6.0-1",
      "2.6.0-1+deb12u1",
      "2.7.0-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48522.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "pyjwt",
      "purl": "pkg:deb/debian/pyjwt?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "2.10.1-2",
      "2.10.1-2+deb13u1",
      "2.10.1-3",
      "2.10.1-4",
      "2.11.0-2",
      "2.12.1-1",
      "2.13.0-1",
      "2.14.0-1",
      "2.15.0-1",
      "2.15.1-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48522.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "2.13.0-1"
          }
        ]
      }
    ],
    "package": {
      "name": "pyjwt",
      "purl": "pkg:deb/debian/pyjwt?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "2.10.1-2",
      "2.10.1-3",
      "2.10.1-4",
      "2.11.0-2",
      "2.12.1-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48522.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #57208 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 17:05:10 GMT
Publisher date: Thu, 28 May 2026 16:16:29 GMT

Read the original announcement