Vulnerabilities

Vulnerability · CVE-2026-26998

Traefik is an HTTP reverse proxy and load balancer.

Published Mar 5, 2026 · catalog updated Jun 17, 2026 · Traefik is an HTTP

Check if you run it

No confirmed exploitation is on record for CVE-2026-26998. EPSS is 0.57%. Act only if a listed version of Traefik is an HTTP is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Traefik is an HTTP).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium4.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.57%
Remediation
Advisory link
Affected products
cpe traefik/traefik

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.

Are you affected?

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  • cpe traefik/traefikversion unspecified

How to fix CVE-2026-26998

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-26998. EPSS is 0.57%. Act only if a listed version of Traefik is an HTTP is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-770: Allocation of Resources Without Limits or Throttling. EPSS 0.57%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 5, 2026 · NIST NVD

    Detected

    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 restr

  2. Jun 17, 2026 · NIST NVD

    Updated

    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 restr

Sources

  • CVE.orgVulnerability recordCVE-2026-26998

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-26998

    30-day exploitation probability 0.6%

    first.org
  • NIST NVDVulnerability recordCVE-2026-26998

    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 authentic

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.