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CVE-2026-54763

⛔ critical
🔍 Scan for this CVE
Summary

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 alongsi

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 Score
10.0
Critical
EPSS Score
0.3
Exploit Probability
Published Date
2026-07-06
First Seen: 2026-07-07
📊 Relative Risk Intelligence

This CVE is Extremely High Risk - more severe than 100.0% of all 338,292 vulnerabilities in our database.

#1
Top 5% most severe
Severity Percentile
🎯 CISA SSVC Assessment Updated: Jul 8, 2026
🔍 Exploitation Status
None
No known exploits
⚙️ Automatable
YES
Can be exploited automatically
💥 Technical Impact
Partial
Limited system impact
SSVC data provided by CISA
Last Modified 2026-07-08
Source NVD 🔗
CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
CVSS Vector 4.0 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/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 IDs (Weakness Types)
CWE-178 CWE-290 CWE-345

📦 Affected Products 3

Vendor Product Status Affected Versions
traefik traefik Affected
< 2.11.51
traefik traefik Affected
> 3.0.0 < 3.6.22
traefik traefik Affected
> 3.7.0 < 3.7.6

🔗 References 3

https://github.com/traefik/traefik/commit/108a526447...
Patch
https://github.com/traefik/traefik/pull/13262
Issue Tracking
https://github.com/traefik/traefik/security/advisori...
Patch Vendor Advisory

🔗 Related CVEs 6

CVE ID Severity CVSS EPSS Summary Published
CVE-2026-54764 🔶 medium 5.8 0.3 Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's ForwardAuth middle... 2026-07-06
CVE-2026-54765 ⚠️ high 8.5 0.4 Traefik is an open source HTTP reverse proxy and load balancer. From v3.7.0 prior to v3.7.6, Traefik's Kubernetes Gatewa... 2026-07-06
CVE-2023-54365 ⚠️ high 7.5 0.6 Traefik before 2.10.5 and 3.0.0-beta4 is affected by a denial-of-service vulnerability in HTTP/2 request handling inheri... 2026-06-23
CVE-2026-48020 ⛔ critical 10.0 0.6 Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulner... 2026-06-23
CVE-2026-48491 ⛔ critical 10.0 0.3 Traefik is an HTTP reverse proxy and load balancer. From 3.7.0 until 3.7.3, there is a high severity vulnerability in Tr... 2026-06-23
CVE-2026-53622 ⛔ critical 10.0 0.2 Traefik is an HTTP reverse proxy and load balancer. Prior to 3.7.3, there is a critical vulnerability in Traefik's HTTP/... 2026-06-23
These CVEs affect the same products