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Fencer Intel
medium 4.3

CVE-2024-6839 json

Improper Regex Path Matching in corydolphin/flask-cors

published last yr. modified 2mo ago also GHSA-7rxf-gvfg-47g4 , PYSEC-2026-1384 , EUVD-2025-6973

cvss
4.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

Summary

corydolphin/flask-cors version 4.0.1 contains an improper regex path matching vulnerability. The plugin prioritizes longer regex patterns over more specific ones when matching paths, which can lead to less restrictive CORS policies being applied to sensitive endpoints. This mismatch in regex pattern priority allows unauthorized cross-origin access to sensitive data or functionality, potentially exposing confidential information and increasing the risk of unauthorized actions by malicious actors.

Patch / fix

  • pypi flask-cors 6.0.0
  • python-flask-cors Debian 12 3.0.10-2+deb12u1
  • python-flask-cors Debian 14, Debian 13 6.0.1-1

debian advisories DEBIAN-CVE-2024-6839

  • python-flask-cors Ubuntu 22.04 LTS 3.0.9-2ubuntu0.1
  • python-flask-cors Ubuntu Pro 20.04 LTS 3.0.8-2ubuntu0.1+esm1
  • python-flask-cors Ubuntu Pro 24.04 LTS 4.0.0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2024-6839

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-Flask-Cors openSUSE Tumbleweed 6.0.2-1.1

opensuse advisories openSUSE-SU-2026:10485-1

Is CVE-2024-6839 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-6839 updated cvss 4.3

flask-cors: Improper Regex Path Matching in corydolphin/flask-cors

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.74% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • huntr.com https://huntr.com/bounties/403eb1fc-86f4-4820-8eba-0f3dfae9f2b4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
OSV 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
GitHub 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi flask-cors
<6.0.0
6.0.0

Affected products

  • corydolphin corydolphin/flask-cors

Classification

Weakness
  • CWE-41 Improper Resolution of Path Equivalence

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.