GHSA-qcm3-7879-xcww: github.com/cilium/cilium (CVE-2024-42487)

Package	Ecosystem	Affected	Fixed in
github.com/cilium/cilium	Go	>=1.16.0, <1.16.1 \|\| >=1.15.0, <1.15.8	1.16.1, 1.15.8

Machine-written summary

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

Cilium versions 1.15.0 through 1.15.7 and 1.16.0 are affected by a Gateway API route matching order bug, where request headers are evaluated before request methods, contrary to the specification. An attacker who can send requests to a gateway whose HTTPRoutes or GRPCRoutes match on both headers and methods may reach an unintended backend and access information meant for other services, especially if that backend has no Network Policy restricting traffic. Upgrade to Cilium 1.15.8 or 1.16.1. The source lists no workaround.

Written 2 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
4.0	Medium	3.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0053, the 45th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:15 UTC First seen by agentprime
31 Oct 2026, 14:15 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.