CVE-2026-32595
published 2026-03-20CVE-2026-32595: Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 comtain BasicAuth middleware that…
PriorityP419low3.7CVSS 3.1
AVNACHPRNUINSUCLINAN
EPSS
0.39%
30.3th percentile
Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 comtain BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | traefik_traefik | 0 – 1.7.34 | — |
| github.com | traefik_traefik_v2 | >= 0 < 2.11.41 | 2.11.41 |
| github.com | traefik_traefik_v2 | >= 0 < 2.11.43 | 2.11.43 |
| github.com | traefik_traefik_v3 | >= 0 < 3.6.11 | 3.6.11 |
| github.com | traefik_traefik_v3 | >= 3.0.0-beta1 < 3.6.14 | 3.6.14 |
| github.com | traefik_traefik_v3 | >= 3.7.0-ea.1 < 3.7.0-ea.2 | 3.7.0-ea.2 |
| github.com | traefik_traefik_v3 | >= 3.7.0-ea.1 < 3.7.0-rc.2 | 3.7.0-rc.2 |
| traefik | traefik | < 2.11.41 | 2.11.41 |
| traefik | traefik | — | — |
| traefik | traefik | — | — |
| traefik | traefik | — | — |
| traefik | traefik | 3.0.0 – 3.6.11 | — |
CVSS provenance
nvdv3.13.7LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
nvdv4.06.3MEDIUMCVSS:4.0/AV:N/AC:H/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
ghsa6.3MEDIUM
vendor_redhat6.3MEDIUM
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GHSA
Traefik: A timing side-channel vulnerability allows for valid username enumeration via BasicAuth middleware
ghsa·2026-04-24·CVSS 6.3
CVE-2026-41263 [MEDIUM] CWE-208 Traefik: A timing side-channel vulnerability allows for valid username enumeration via BasicAuth middleware
Traefik: A timing side-channel vulnerability allows for valid username enumeration via BasicAuth middleware
## Summary
There is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences.
The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring authentication response times.
## Patches
- https://github.com/traefik/traefik/releases/tag/v2.11.43
- https://github.com/traefik/traefik/releases/tag/v3.6.14
- ht
OSV
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration in github.com/traefik/traefik
osv·2026-03-23
CVE-2026-32595 Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration in github.com/traefik/traefik
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration in github.com/traefik/traefik
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration in github.com/traefik/traefik
GHSA
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration
ghsa·2026-03-20
CVE-2026-32595 [MEDIUM] CWE-208 Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration
## Summary
There is a potential vulnerability in Traefik's BasicAuth middleware that allows username enumeration via a timing attack.
When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames.
## Patches
- https://github.com/traefik/traefik/releases/tag/v2.11.41
- https://github.com/traefik/traefik/releases/tag/v3.6.11
- https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2
## For more information
If you have any questions or
OSV
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration
osv·2026-03-20
CVE-2026-32595 [MEDIUM] Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration
Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration
## Summary
There is a potential vulnerability in Traefik's BasicAuth middleware that allows username enumeration via a timing attack.
When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames.
## Patches
- https://github.com/traefik/traefik/releases/tag/v2.11.41
- https://github.com/traefik/traefik/releases/tag/v3.6.11
- https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2
## For more information
If you have any questions or
Red Hat
traefik: Traefik: Username enumeration via timing attack in BasicAuth middleware
vendor_redhat·2026-03-20·CVSS 6.3
CVE-2026-32595 [MEDIUM] CWE-208 traefik: Traefik: Username enumeration via timing attack in BasicAuth middleware
traefik: Traefik: Username enumeration via timing attack in BasicAuth middleware
Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 comtain BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.
A flaw was found in Traefik. An unauthenticated attacker can exploit a timing attack vulnerability in the BasicA
No detection rules found.
No public exploits indexed.
2026-03-20
Published