CVE-2026-41181
published 2026-05-15CVE-2026-41181: Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.44, 3.6.15, and 3.7.0-rc.3, there is an information disclosure vulnerability in Traefik's…
PriorityP433medium5.8CVSS 3.1
AVNACLPRNUINSCCLINAN
EPSS
0.45%
35.6th percentile
Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.44, 3.6.15, and 3.7.0-rc.3, there is an information disclosure vulnerability in Traefik's errors (custom error pages) middleware. When the backend returns a response matching the configured status range, the middleware forwards the original request's complete header set, including Authorization, Cookie, and other authentication material, to the separate error page service rather than only the minimal context needed to render the error page. This behavior is undocumented: the documentation states only that Host is forwarded by default, so operators are not warned that sensitive credentials are shared across service boundaries. Deployments using the errors middleware with a distinct error page service may inadvertently expose end-user credentials to infrastructure that was not intended to receive them. This vulnerability is fixed in 2.11.44, 3.6.15, and 3.7.0-rc.3.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| devspaces | traefik-rhel9 | — | — |
| github.com | traefik_traefik_v2 | >= 0 < 2.11.44 | 2.11.44 |
| github.com | traefik_traefik_v3 | >= 0 < 3.6.15 | 3.6.15 |
| github.com | traefik_traefik_v3 | >= 3.7.0-rc.0 < 3.7.0-rc.3 | 3.7.0-rc.3 |
| traefik | traefik | < 2.11.43 | 2.11.43 |
| traefik | traefik | < 2.11.44 | 2.11.44 |
| traefik | traefik | — | — |
| traefik | traefik | — | — |
| traefik | traefik | — | — |
| traefik | traefik | >= 3.0.0 < 3.6.15 | 3.6.15 |
CVSS provenance
nvdv3.15.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
nvdv4.06.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/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
vendor_redhat5.8MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
GHSA
Traefik's errors middleware forwards Authorization and Cookie headers to separate error page service
ghsa·2026-05-04
CVE-2026-41181 [MEDIUM] CWE-201 Traefik's errors middleware forwards Authorization and Cookie headers to separate error page service
Traefik's errors middleware forwards Authorization and Cookie headers to separate error page service
## Summary
There is a medium severity information disclosure vulnerability in Traefik's `errors` (custom error pages) middleware. When the backend returns a response matching the configured status range, the middleware forwards the original request's complete header set, including `Authorization`, `Cookie`, and other authentication material, to the separate error page service rather than only the minimal context needed to render the error page. This behavior is undocumented: the documentation states only that `Host` is forwarded by default, so operators are not warned that sensitive credentials are shared across service boundaries. Deployments using the `errors` middleware with a distinct
Red Hat
traefik: Traefik: Information disclosure via errors middleware exposing user credentials
vendor_redhat·2026-05-15·CVSS 5.8
CVE-2026-41181 [MEDIUM] CWE-201 traefik: Traefik: Information disclosure via errors middleware exposing user credentials
traefik: Traefik: Information disclosure via errors middleware exposing user credentials
Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.44, 3.6.15, and 3.7.0-rc.3, there is an information disclosure vulnerability in Traefik's errors (custom error pages) middleware. When the backend returns a response matching the configured status range, the middleware forwards the original request's complete header set, including Authorization, Cookie, and other authentication material, to the separate error page service rather than only the minimal context needed to render the error page. This behavior is undocumented: the documentation states only that Host is forwarded by default, so operators are not warned that sensitive credentials are shared across service boundaries. Deployment
No detection rules found.
No public exploits indexed.
2026-05-15
Published