CVE-2025-62706

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.5, Authlib’s JWE zip=DEF path performs unbounded DEFLATE decompression. A very small ciphertext can expand into tens or hundreds of megabytes on decrypt, allowing an attacker who can supply decryptable tokens to exhaust memory and CPU and cause denial of service. This issue has been patched in version 1.6.5. Workarounds for this issue involve rejecting or stripping zip=DEF for inbound JWEs at the application boundary, forking and add a bounded decompression guard via decompressobj().decompress(data, MAX_SIZE)) and returning an error when output exceeds a safe limit, or enforcing strict maximum token sizes and fail fast on oversized inputs; combine with rate limiting.
Configurations

No configuration.

History

22 Oct 2025, 22:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-10-22 22:15

Updated : 2025-10-22 22:15


NVD link : CVE-2025-62706

Mitre link : CVE-2025-62706

CVE.ORG link : CVE-2025-62706


JSON object : View

Products Affected

No product.

CWE
CWE-400

Uncontrolled Resource Consumption

CWE-770

Allocation of Resources Without Limits or Throttling