CVE-2025-47278

LOW EPSS 4.8%
Published May 13, 20251y ago · Modified Jun 17, 20262w ago
1.8 CVSS 4.0
Low
Find Similar
Published May 13, 2025 1y ago
Last Modified Jun 17, 2026 2w ago

Description

Flask is a web server gateway interface (WSGI) web application framework. In Flask 3.1.0, the way fallback key configuration was handled resulted in the last fallback key being used for signing, rather than the current signing key. Signing is provided by the `itsdangerous` library. A list of keys can be passed, and it expects the last (top) key in the list to be the most recent key, and uses that for signing. Flask was incorrectly constructing that list in reverse, passing the signing key first. Sites that have opted-in to use key rotation by setting `SECRET_KEY_FALLBACKS` care likely to unexpectedly be signing their sessions with stale keys, and their transition to fresher keys will be impeded. Sessions are still signed, so this would not cause any sort of data integrity loss. Version 3.1.1 contains a patch for the issue.

CVSS Details

Base Score
1.8
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:L/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
Attack Vector Local
Attack Complexity Low
Privileges Required High
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
4.8% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-683

References 3

  • github.com https://github.com/pallets/flask/commit/73d6504063bfa00666a92b07a28aaf906c532f09
  • github.com https://github.com/pallets/flask/releases/tag/3.1.1
  • github.com https://github.com/pallets/flask/security/advisories/GHSA-4grg-w6v8-c28g

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.