CVE-2026-112778: traefik Auth Bypass — Fix

Description

Traefik before 2.11.46, 3.x before 3.6.17, and 3.7.0 lack namespace validation for Ingress and Service annotations in the Kubernetes Ingress provider, allowing references to Middlewares, ServersTransports, and TLSOptions in other namespaces. Attackers able to create or update Ingress or Service resources in one namespace can set router.middlewares or service.serverstransport annotations to obtain another tenant's injected credentials or reuse its client certificates, bypassing namespace-based tenant isolation.

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-862 Missing Authorization

Affected Products

Vendor	Product	Versions
traefik	traefik	< 2.11.46
traefik	traefik	3.0.0 — 3.6.16
traefik	traefik	All

References

Advisories & Patches

https://github.com/traefik/traefik/security/advisories/GHSA-rh7m-2m44-x32f

Other References

https://www.vulncheck.com/advisories/traefik-before-2.11.46-3.6.17-and-3.7.1-cross-namespace-resource-reference-via-kubernetes-annotations

Frequently Asked Questions

What is CVE-2026-112778? +

Traefik before 2.11.46, 3.x before 3.6.17, and 3.7.0 lack namespace validation for Ingress and Service annotations in the Kubernetes Ingress provider, allowing references to Middlewares, ServersTransports, and TLSOptions in other namespaces. Attackers able to create or update Ingress or Service resources in one namespace can set router.middlewares or service.serverstransport annotations to obtain another tenant's injected credentials or reuse its client certificates, bypassing namespace-based tenant isolation. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-112778? +

CVE-2026-112778 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-112778? +

CVE-2026-112778 affects products from traefik, specifically: traefik. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-112778? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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