Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Critical, CVSS 9.1amended

Traefik: Authentication Bypass via Path Traversal in ReplacePathRegex Middleware

CVE-2026-65600GHSA-cxjq-mrr5-89rv

What to do

Partial vendor fix. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • Go github.com/traefik/traefik/v3

    Affected
    <= 3.6.22>= 3.7.0, <= 3.7.6
    Fixed in
    3.7.7, 3.6.23

  • Go github.com/traefik/traefik/v2

    Affected
    <= 2.11.51
    Fixed in
    2.11.52

  • Go github.com/traefik/traefik

    Affected
    <= 1.7.34
    Fixed in
    no fixed version recorded

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
9.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
  • CVE-2026-65600: 0.62% estimated exploitation activity in the next 30 days; percentile 49.84 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Summary There is a critical authentication-bypass vulnerability in Traefik's ReplacePathRegex middleware. When it is configured with a regular expression that captures user-controlled path segments without a mandatory separator (for example regex: "^/api(.)", replacement: "/$1"), a crafted request can produce an un-normalized replacement path such as /../admin, which Traefik forwarded to the backend without validation. A backend that normalizes the path may resolve it to a protected route, letting an unauthenticated attacker reach resources located behind authentication middleware. This is the same class of issue that was fixed for StripPrefix in CVE-2026-48020; that post-replacement normalization check had not been applied to ReplacePathRegex. The fix rejects any request whose replaced path does not match its normalized form. Patches - https://github.com/traefik/traefik/releases/tag/v2.11.52 - https://github.com/traefik/traefik/releases/tag/v3.6.23 -…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 3 · amended ·

    Amended from ghsa record GHSA-cxjq-mrr5-89rv

  2. Revision 2 · amended ·

    Amended from osv record GO-2026-6208

  3. Revision 1 · created ·

    Published from osv record GHSA-cxjq-mrr5-89rv

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-65600

Advisory: Traefik: Authentication Bypass via Path Traversal in ReplacePathRegex Middleware
IDs: CVE-2026-65600, GHSA-cxjq-mrr5-89rv
Record: https://patchnext.com/advisories/cve-2026-65600 (revision 3, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/traefik/traefik/v3 3.7.7, 3.6.23; github.com/traefik/traefik/v2 2.11.52. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/traefik/traefik/v3: affected <= 3.6.22; >= 3.7.0, <= 3.7.6; fixed in 3.7.7, 3.6.23
- Go github.com/traefik/traefik/v2: affected <= 2.11.51; fixed in 2.11.52
- Go github.com/traefik/traefik: affected <= 1.7.34

## Suggested inspection (read-only)
- Go github.com/traefik/traefik/v3: check the installed version with your package manager.
- Go github.com/traefik/traefik/v2: check the installed version with your package manager.
- Go github.com/traefik/traefik: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/traefik/traefik/v3, github.com/traefik/traefik/v2, github.com/traefik/traefik.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-cxjq-mrr5-89rv (OSV record GHSA-cxjq-mrr5-89rv lists affected ranges: Go github.com/traefik/traefik/v2 >=0 =0 =3.7.0 =0 <=1.7.34)
- Verified: https://osv.dev/vulnerability/GO-2026-6208 (OSV record GO-2026-6208 lists affected ranges: Go github.com/traefik/traefik >=0; Go github.com/traefik/traefik/v2 >=0 =0 =3.7.0 <3.7.7 (fixed))
- Verified: https://github.com/advisories/GHSA-cxjq-mrr5-89rv (GitHub-reviewed advisory GHSA-cxjq-mrr5-89rv lists affected ranges: Go github.com/traefik/traefik/v2 >=0 =0 =3.7.0 =0 <=1.7.34)

Commands are suggestions: review each one before running it.

Loading voting…