CVE-2026-42551

HIGHCVSS 7.5/10EPSS 0.31%

Last modified

CVE-2026-42551 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Flight is an extensible micro-framework for PHP. Prior to 3.18.1, Request::getMethod() unconditionally honors the X-HTTP-Method-Override header and the $_REQUEST['_method'] parameter on any HTTP verb (including safe verbs such as GET), with no opt-in and no whitelist of permitted target methods. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

Flight is an extensible micro-framework for PHP. Prior to 3.18.1, Request::getMethod() unconditionally honors the X-HTTP-Method-Override header and the $_REQUEST['_method'] parameter on any HTTP verb (including safe verbs such as GET), with no opt-in and no whitelist of permitted target methods. A GET request can silently become a DELETE or PUT, enabling CSRF escalation against destructive endpoints, bypass of middleware gated on unsafe verbs, and cache poisoning between CDN and origin. This vulnerability is fixed in 3.18.1.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability
0.31%

22.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-42551?
Flight is an extensible micro-framework for PHP. Prior to 3.18.1, Request::getMethod() unconditionally honors the X-HTTP-Method-Override header and the $_REQUEST['_method'] parameter on any HTTP verb (including safe verbs such as GET), with no opt-in and no whitelist of permitted target methods. A GET request can silently become a DELETE or PUT, enabling CSRF escalation against destructive endpoints, bypass of middleware gated on unsafe verbs, and cache poisoning between CDN and origin. This vulnerability is fixed in 3.18.1.
How severe is CVE-2026-42551?
CVE-2026-42551 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.
How do I fix CVE-2026-42551?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-42551?

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Source: NVD / NIST