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CVE-2020-5255

Prevent cache poisoning via a Response Content-Type header

MEDIUM
4.3
CVSS Score
Published: March 30, 2020 at 07:30 PM UTC
Updated: June 17, 2026 at 03:21 AM UTC
2 products affected across 2 vendorsSymfonySymfony

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Severity
MEDIUM4.3
Exploit prediction
EPSS 1%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Symfony· Sensiolabsdrupal
95%
4.4.0 ≤ v < 4.4.75.0.0 ≤ v < 5.0.7
Affected range stops below 4.4.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.0.7, so it looks safe — our inference, not a vendor statement
Symfony· Symfonycomposer
60%
v < 4.4.7v < 5.0.7
Affected range stops below 4.4.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.0.7, so it looks safe — our inference, not a vendor statement

References (4)

x_refsource_MISCPatchThird Party Advisory
Source: [email protected]
https://github.com/symfony/symfony/commit/dca343442e6a954f96a2609e7b4e9c21ed6d74e6
x_refsource_CONFIRMThird Party Advisory
Source: [email protected]
https://github.com/symfony/symfony/security/advisories/GHSA-mcx4-f5f5-4859
Vendor Advisoryx_refsource_FEDORA
Source: [email protected]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/C36JLPHUPKDFAX6D5WYFC4ALO2K7RDUQ/
x_refsource_MISCThird Party Advisory
Source: [email protected]
https://symfony.com/blog/cve-2020-5255-prevent-cache-poisoning-via-a-response-content-type-header

CVSS

4.3MEDIUM[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-435CWE-20

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