Secuno
ENNL
Book demo

CVE-2026-54763

Traefik authentication bypass

10.0 CRITICALEPSS 0.24%
  1. Published6 Jul 2026

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth, DigestAuth, and ForwardAuth middlewares strip canonical-cased spoofed identity headers before writing Traefik's own value, but do not account for underscore-variant header names, which many backends normalize identically to dashed forms. An attacker able to reach a protected route can inject an underscore-variant header that survives Traefik's stripping and reaches the backend alongside, or on the unauthenticated ForwardAuth authResponseHeaders path instead of, the value Traefik intended to set, spoofing identity or authorization context. This issue is fixed in versions v2.11.51, v3.6.22, and v3.7.6.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Affected products

Traefik≥ 3.0.0 < 3.6.22 · ≥ 3.7.0 < 3.7.6 · < 2.11.51

Remediation

Fixed in
Traefik≥ 3.6.22

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-1089719.6
A flaw has been found in D-Link DCS-930L B1.08B4. This impacts the function mpfd_decode…
CVE-2026-935829.4
The HTTP Basic Authentication modules in ((OTRS)) Community Edition 6 and prior accept…
CVE-2026-1065038.1
Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1,…
CVE-2026-1021618.8
An unauthenticated attacker located on an adjacent private network (or any attacker…
CVE-2026-1056409.1
Plane is an open-source project management tool. Prior to 1.4.0, Plane trusts email…
CVE-2026-1052159.1
ZITADEL before 3.4.14 and 4.x before 4.16.2 contains an authentication bypass in the…

Frequently asked

Is CVE-2026-54763 being actively exploited?

CVE-2026-54763 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.24%.

How severe is CVE-2026-54763?

CVE-2026-54763 has a CVSS 3.1 base score of 10.0, rated critical. EPSS estimates a 0.24% probability of exploitation.

Which products are affected by CVE-2026-54763?

Affected products include Traefik.

How do I fix CVE-2026-54763?

Upgrade affected software to a fixed version, for example Traefik 3.6.22 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-54763 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.