CVE-2026-6540
L7 policy bypass via unnormalized HTTP path matching
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.
INFO
Published Date :
July 30, 2026, 3:16 p.m.
Last Modified :
July 30, 2026, 4:43 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-6540
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | e6d453f4-3dae-4941-bcea-9af25f4e824d | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Enable Calico's Application Layer Policy.
- Ensure HTTP rules normalize URLs correctly.
- Configure Dikastes for strict path evaluation.
- Update Calico and related components.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6540.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6540 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6540
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6540 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-6540 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jul. 30, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Tigera', 'product': 'Calico', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.31.6', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}, {'vendor': 'Tigera', 'product': 'Calico Enterprise', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.21.7', 'versionType': 'semver'}, {'status': 'affected', 'version': '3.22.0', 'lessThan': '3.22.4', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}, {'vendor': 'Tigera', 'product': 'Calico Cloud', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '22.4.0', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-22 Added CWE CWE-23 Added Reference https://github.com/projectcalico/calico/pull/12531 Added Reference https://github.com/projectcalico/calico/pull/12532 Added Reference https://github.com/projectcalico/calico/pull/12533 Added Reference https://www.tigera.io/security-bulletins/tta-2026-005/