CVE-2026-26998

4.4 MEDIUM
Published: March 05, 2026 Modified: March 06, 2026
View on NVD

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing the ForwardAuth middleware responses. When Traefik is configured to use the ForwardAuth middleware, the response body from the authentication server is read entirely into memory without any size limit. There is no maxResponseBodySize configuration to restrict the amount of data read from the authentication server response. If the authentication server returns an unexpectedly large or unbounded response body, Traefik will allocate unlimited memory, potentially causing an out-of-memory (OOM) condition that crashes the process. This results in a denial of service for all routes served by the affected Traefik instance. This issue has been patched in versions 2.11.38 and 3.6.9.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/traefik/traefik/releases/tag/v2.11.38
Source: security-advisories@github.com
Product Release Notes
https://github.com/traefik/traefik/releases/tag/v3.6.9
Source: security-advisories@github.com
Product Release Notes
https://github.com/traefik/traefik/security/advisories/GHSA-fw45-f5q2-2p4x
Source: security-advisories@github.com
Patch Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
4.4 / 10.0
EPSS (Exploit Probability)
0.0%
7th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

traefik