CVE-2026-6540: L7 policy bypass via unnormalized HTTP path matching

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-30 · updated 2026-08-08
Weakness: CWE-22

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.

Affected products

Tigera Calico: before 3.21.7; before 3.31.6; through 22.4.0; from 3.22.0 before 3.22.4; from 3.32.0 before 3.32.1 — fixed in 3.21.7, 3.22.4, 3.31.6, 3.32.1

How to fix

Upgrade to a fixed version: Tigera Calico 3.21.7, 3.22.4, 3.31.6, 3.32.1. Check the vendor advisory for mitigations.

References

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