CVE-2026-6540 L7 policy bypass via unnormalized HTTP path matching
Attackers can bypass Calico HTTP policies using unnormalized paths to access restricted endpoints when Application Layer Policy is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-6540?
CVE-2026-6540 is a high-severity path traversal vulnerability in Tigera Calico, published on 30 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Calico's Application Layer Policy (disabled by default), which enforces HTTP rules through Dikastes, fails to perform URL path normalization. As a result, HTTP requests using path-traversal segments, encoded slashes, or repeated slashes are not correctly evaluated by Prefix path rules. Dikastes authorizes the request under the permitted prefix while the downstream workload or a fronting proxy normalizes the path and serves the restricted endpoint. An attacker with network access and no special RBAC can potentially reach HTTP endpoints the policy was intended to restrict.
Which versions are affected by CVE-2026-6540?
It affects 1 product.
Products include Tigera Calico.
How do I fix CVE-2026-6540?
Apply the vendor's patch.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-6540 being exploited?
There is no known exploitation of CVE-2026-6540 in the wild and no public exploit code.
Other vulnerabilities in Tigera Calico
- CVE-2026-41187 Calico Tier Authorization Bypass via DeleteCollection
- CVE-2026-41186 Unauthenticated Go pprof exposure in Calico debug server
- CVE-2026-41184 ServiceAccount token disclosure via install-cni container logs
- CVE-2026-41185 ServiceAccount token disclosure via Azure IPAM CNI plugin logs
- CVE-2022-28224 Calico and Calico Enterprise may be vulnerable to route hijacking with the floating IP feature
Sources
Also known as GHSA-gm75-wg2c-p77x, MINI-4cpr-c729-63p6, MINI-4xf7-5cpv-mf2v, MINI-h3fq-4r7h-fmwp, MINI-m625-vpcf-mf7h, MINI-pc8f-phx3-x985 and 1 more.