CVE-2026-48525

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Source
https://cve.org/CVERecord?id=CVE-2026-48525
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-48525.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-48525
Aliases
Downstream
Related
Published
2026-05-28T15:11:12.483Z
Modified
2026-06-24T18:29:32.458809978Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
PyJWT: Unauthenticated DoS via unbounded Base64URL decoding of unused payload segment in b64=false detached JWS
Details

PyJWT is a JSON Web Token implementation in Python. From 2.8.0 to 2.12.1, when verifying detached JWS tokens using the unencoded-payload option ("b64": false, RFC 7797), PyJWT performs Base64URL decoding of the compact-serialization payload segment before enforcing the detached-payload rules. For b64=false, PyJWT later discards that decoded payload and replaces it with the caller-provided detached_payload. In practice, this turns the middle segment into an attacker-controlled “work amplifier”: a remote client can supply an arbitrarily large Base64URL payload segment that forces CPU work + memory allocations even if the signature is invalid. This creates an unauthenticated DoS vector against any endpoint that verifies detached JWS using PyJWT. This vulnerability is fixed in 2.13.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48525.json"
}
References

Affected packages

Git / github.com/jpadilla/pyjwt

Affected ranges

Type
GIT
Repo
https://github.com/jpadilla/pyjwt
Events
Introduced
72ad55f6d7041ae698dc0790a690804118be50fc
Fixed
7144e4534c34810f4525dc4578a32addd8212cff
Database specific 
{
    "cpe": "cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ],
    "extracted_events": [
        {
            "introduced": "2.8.0"
        },
        {
            "fixed": "2.13.0"
        },
        {
            "introduced": "2.8.0"
        },
        {
            "last_affected": "2.12.1"
        }
    ]
}

Affected versions

2.*
2.10.0
2.10.1
2.11.0
2.12.0
2.12.1
2.8.0
2.9.0

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-48525.json"