CVE-2024-6844: corydolphin/flask-cors · Origin Validation Error
Affects corydolphin/flask-corsSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium.
Data as of 26 Oct 2026, 07:57 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubcorydolphin/flask-corspkg:github/corydolphin/flask-corsOther threats | Affected
| Fixed in– |
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AI-suggested
To mitigate CVE-2024-6844, European organizations should take the following specific actions: 1) Immediately audit all Flask applications using flask-cors to identify affected versions and usage patterns. 2) Review CORS configurations to ensure strict origin validation and avoid relying solely on path-based matching that could be affected by URL normalization issues. 3) Implement custom CORS validation logic that correctly handles '+' characters in URL paths without using unquote_plus or similar functions that alter the path semantics. 4) Monitor official flask-cors repositories and security advisories for patches or updates addressing this vulnerability and apply them promptly once available. 5) Consider deploying Web Application Firewalls (WAFs) with rules to detect and block suspicious cross-origin requests that do not conform to expected patterns. 6) Conduct penetration testing focused on CORS misconfigurations to identify potential unauthorized access vectors. 7) Educate developers about the risks of improper URL normalization in security-critical components like CORS enforcement. 8) If immediate patching is not possible, restrict CORS policies to trusted origins only and minimize the attack surface by disabling CORS where not strictly necessary.
Description
A vulnerability in corydolphin/flask-cors version 4.0.1 allows for inconsistent CORS matching due to the handling of the '+' character in URL paths. The request.path is passed through the unquote_plus function, which converts the '+' character to a space ' '. This behavior leads to incorrect path normalization, causing potential mismatches in CORS configuration. As a result, endpoints may not be matched correctly to their CORS settings, leading to unexpected CORS policy application. This can cause unauthorized cross-origin access or block valid requests, creating security vulnerabilities and usability issues.