CVE-2026-48525

MEDIUM EPSS 20.4%
Published May 28, 20261mo ago · Modified Jun 17, 20261w ago
5.3 CVSS 3.1
Medium
Find Similar
Published May 28, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
5.3
Exploitability
3.9
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability Low

Threat Intelligence

EPSS Exploit Probability
20.4% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-400 Uncontrolled Resource Consumption Resource Mgmt

Affected Products 1

VendorProductVersionRange
pyjwt_projectpyjwt*≥2.8.0  –  ≤2.12.1

References 1

  • github.com https://github.com/jpadilla/pyjwt/security/advisories/GHSA-w7vc-732c-9m39
    ExploitMitigationVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.