Answer in brief
CVE-2026-54763 records a Critical severity (CVSS 10.0) vulnerability in Traefik: headerField underscore-variant identity spoofing in BasicAuth / DigestAuth / ForwardAuth. The current sources do not mark it as known exploited. The current feed maps traefik/traefik (generic), github.com/traefik/traefik/v2 (go), github.com/traefik/traefik/v3 (go), github.com/traefik/traefik/v3 (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-54763 records a Critical severity (CVSS 10.0) vulnerability in Traefik: headerField underscore-variant identity spoofing in BasicAuth / DigestAuth / ForwardAuth. The current sources do not mark it as known exploited. The current feed maps traefik/traefik (generic), github.com/traefik/traefik/v2 (go), github.com/traefik/traefik/v3 (go), github.com/traefik/traefik/v3 (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 10.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps traefik/traefik (generic), github.com/traefik/traefik/v2 (go), github.com/traefik/traefik/v3 (go), github.com/traefik/traefik/v3 (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| traefik/traefikgeneric | < 2.11.51 || >= 3.0.0-beta1, < 3.6.22 || >= 3.7.0-ea.1, < 3.7.6 | Not reported |
| github.com/traefik/traefik/v2go | <=2.11.50 | 2.11.51 |
| github.com/traefik/traefik/v3go | <=3.6.21 | 3.6.22 |
| github.com/traefik/traefik/v3go | >=3.7.0,<=3.7.5 | 3.7.6 |
Published upstream
Jul 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.
CVSS is 10.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps traefik/traefik (generic), github.com/traefik/traefik/v2 (go), github.com/traefik/traefik/v3 (go), github.com/traefik/traefik/v3 (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| traefik/traefikgeneric | < 2.11.51 || >= 3.0.0-beta1, < 3.6.22 || >= 3.7.0-ea.1, < 3.7.6 | Not reported |
| github.com/traefik/traefik/v2go | <=2.11.50 | 2.11.51 |
| github.com/traefik/traefik/v3go | <=3.6.21 | 3.6.22 |
| github.com/traefik/traefik/v3go | >=3.7.0,<=3.7.5 | 3.7.6 |
Published upstream
Jul 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.