CVSS 3.1
4.3 mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LCVE-2020-5255
Medium (4.3) in sensiolabs symfony. EPSS 1.3% chance of exploitation in the next 30 days.
In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.
Severity
- EPSS
- 1.3% chance of exploitation in the next 30 days; higher than 70% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-20, CWE-435
- Published
- Modified
- Record from
- the NVD, synced
Affected
- sensiolabs:symfony
References
- https://github.com/symfony/symfony/commit/dca343442e6a954f96a2609e7b4e9c21ed6d74e6
- https://github.com/symfony/symfony/security/advisories/GHSA-mcx4-f5f5-4859
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/C36JLPHUPKDFAX6D5WYFC4ALO2K7RDUQ/
- https://symfony.com/blog/cve-2020-5255-prevent-cache-poisoning-via-a-response-content-type-header
- https://github.com/symfony/symfony/commit/dca343442e6a954f96a2609e7b4e9c21ed6d74e6