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🛡️ CVE-2024-6839 — flask-cors

🟡 CVSS 5.3 — Medium ⚠️ Exploit Public CWE-41 OSV
5.3
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Flask-CORS improper regex path matching vulnerability

corydolphin/flask-cors version 5.0.1 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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity none, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
  • Integrity impact: None.
  • Availability impact: None.

Weakness class

CVE-2024-6839 is classified as CWE-41: Improper Resolution of Path Equivalence. The product is vulnerable to file system contents disclosure through path equivalence.

Affected software

CVE-2024-6839 is recorded against 1 package.

  • flask-cors (fixed in 6.0.0)

Timeline and source

Published on 20 March 2025 and last revised on 7 July 2026. A public exploit is known to exist, which raises the urgency of patching considerably. Record sourced from OSV.

References

nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
github.com (Web)
huntr.com (Web)
lists.debian.org (Web)

Other advisories for this package

flask-cors has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-41: Improper Resolution of Path Equivalence) in other software:

CVE-2024-6839 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity MEDIUM
CVSS Score 5.3
CVSS Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
CWE CWE-41
Public Exploit ⚠️ Yes
Source OSV
Published 2025-03-20
Updated 2026-08-20
Modified 2026-07-07
Fix URL N/A

Affected Packages

Software From version Fixed in
flask-cors — 6.0.0

Exploit Protection

Are you running flask-cors?

CVE-2024-6839 carries CVSS 5.3 Medium rating and a public exploit already exists. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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