SECUFOCUSNOW
Home›CVE index›CVE-2026-40912
Review reviewHigh

CVE-2026-40912

traefik traefik, Red Hat OpenShift Dev Spaces 3.28

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment pa...

CVSS
7.8
EPSS
0.77%
52.0% percentile
CISA KEV
Not listed
Published
2026.05.01
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.77%
Technical severityCVSS 7.8

Vulnerability overview

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment pa...

Affected product and versions

Product
traefik traefik, Red Hat OpenShift Dev Spaces 3.28
Affected versions
>= < 2.11.43, >= >= 3.0.0-beta1, < 3.6.14, >= >= 3.7.0-ea.1, < 3.7.0-rc.2, < 2.11.43, >= 3.0.0 < 3.6.14, 3.7.0
Fixed versions
2.11.43, 3.6.14

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that traefik traefik, Red Hat OpenShift Dev Spaces 3.28 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N/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
CWE
CWE-22, CWE-706
CVE-2026-40912 — traefik traefik, Red Hat OpenShift Dev Spaces 3.28 | SECUFOCUS NOW