# 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.

- **Severity:** High 7.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jul 2026
- **Updated:** 30 Jul 2026
- **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, MINI-qvxq-xr2q-5c87

## 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.

Weakness: CWE-23 (Relative Path Traversal), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-6540?

It affects 1 product.


Products: Tigera Calico.

## How do I fix CVE-2026-6540?

Apply the vendor's patch.

## 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](https://insights.sbomify.com/CVE-2026-41187/): Calico Tier Authorization Bypass via DeleteCollection (medium 6.2)
- [CVE-2026-41186](https://insights.sbomify.com/CVE-2026-41186/): Unauthenticated Go pprof exposure in Calico debug server (medium 6.0)
- [CVE-2026-41184](https://insights.sbomify.com/CVE-2026-41184/): ServiceAccount token disclosure via install-cni container logs (medium 6.0)
- [CVE-2026-41185](https://insights.sbomify.com/CVE-2026-41185/): ServiceAccount token disclosure via Azure IPAM CNI plugin logs (medium 6.0)
- [CVE-2022-28224](https://insights.sbomify.com/CVE-2022-28224/): Calico and Calico Enterprise may be vulnerable to route hijacking with the floating IP feature (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6540 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-6540 in the wild and no public exploit code.

Affected product: Tigera Calico. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-6540/ (Markdown: https://insights.sbomify.com/CVE-2026-6540/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6540
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6540
- OSV: https://osv.dev/vulnerability/CVE-2026-6540

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6540/
Summaries are generated and may contain mistakes; the official description above is the record.