1.8

CVE-2025-47278: pallets flask

CVSS: 1.8v4.0LowDeferred
AliasesGHSA-4grg-w6v8-c28gPYSEC-2026-1377UBUNTU-CVE-2025-47278
Published 13-05-2025Last modified 13-05-2025
Open JSON

Vulnerability summary

CVE-2025-47278 is a low (CVSS 1.8) vulnerability in pallets flask. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8% of scored vulnerabilities.

Overall risk
7/100
0100
Minimal · default modelHow is this calculated?
CVSS score
1.8/10
010
Low · v4.0 (CVE.org)
EPSS score
0.19%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 3
CGA-PCX4-JWPH-2G77CGA-RGFV-MJ9P-W4PGCGA-VM4C-FH4W-WVG5

Timeline

  1. 13-05-2025
    PublishedVulnerability first disclosed.
  2. 13-05-2025
    Last modifiedVulnerability information updated.

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 metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

+0.01 pp

From 0.18% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.19%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard21 products
  • airflow-3< 3.0.1-r1
  • airflow-3-bitnami-compat< 3.0.1-r1
  • airflow-3-compat< 3.0.1-r1
  • airflow-3-iamguarded-compat< 3.0.1-r1
  • airflow-core-3< 3.0.1-r1
Wolfi15 products
  • airflow-3< 3.0.1-r1
  • airflow-3-bitnami-compat< 3.0.1-r1
  • airflow-3-compat< 3.0.1-r1
  • airflow-3-iamguarded-compat< 3.0.1-r1
  • emissary< 3.10.0-r3
Debian1 product
  • flask< 3.1.1-1
Opensuse1 product
  • python-Flask&distro=openSUSE Tumbleweed< 3.1.1-1.1
Pallets1 product
PyPI1 product
  • flask≥ 3.1.0, < 3.1.1
Ubuntu1 product
  • flask< 3.1.0-2ubuntu1.1

7 vendors · 41 products

References

14 links
Show all 14 references