GHSA-vxrr-w42w-w76g: flightphp/core (CVE-2026-42551)

Package	Ecosystem	Affected	Fixed in
flightphp/core	Packagist	<3.18.1	3.18.1

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The flightphp/core Packagist package, versions before 3.18.1, honors the X-HTTP-Method-Override header and the _method parameter on any HTTP verb, including GET, so a GET request can be treated as DELETE or PUT. An attacker can exploit this with a crafted link or page that triggers a request on a victim's browser, which can reach destructive routes and bypass middleware gated on unsafe verbs. Upgrade to 3.18.1, where the new flight.allow_method_override setting can be set to false to disable both override methods.

Written 3 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
7.5	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0035, the 28th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:25 UTC First seen by agentprime
31 Oct 2026, 14:25 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.