Vulnerability · Published May 13, 2026 · Assigned by GitHub_M

CVE-2026-42551Flight: HTTP method override enabled by default enables CSRF escalation and middleware bypass in flightphp/core

High 7.5

In plain English

A high-severity security flaw in core from flightphp. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 71.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	flightphp/core	3.18.1	GHSA-vxrr-w42w-w76g

Affected products (as reported)

Vendor	Product	Versions
flightphp	core	< 3.18.1

Weakness: CWE-436 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

https://github.com/flightphp/core/security/advisories/GHSA-vxrr-w42w-w76g x_refsource_CONFIRM