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Fencer Vulns
low 3.7

CVE-2026-32595 json

Traefik: BasicAuth Middleware Timing Attack Allows Username Enumeration

published 2026-03-20 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-13664 , GHSA-g3hg-j4jv-cwfr , GO-2026-4792

cvss
3.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/traefik/traefik/v2 2.11.41
  • go github.com/traefik/traefik/v3 3.6.11, 3.7.0-ea.2
  • traefik traefik 2.11.41, 3.6.11, 3.7.0-ea.2
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260326T203309-150000.1.155.2

suse advisories SUSE-SU-2026:1135-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • traefik openSUSE Tumbleweed 3.6.12-1.1
  • traefik2 openSUSE Tumbleweed 2.11.42-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10444-1openSUSE-SU-2026:10445-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-32595 updated cvss 5.3

traefik: Traefik: Username enumeration via timing attack in BasicAuth middleware

  • Red Hat OpenShift Dev Spaces devspaces/traefik-rhel9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N
CNA 4.0 6.3 CVSS: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
NVD 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
go github.com/traefik/traefik
<=1.7.34
all versions
 no fix listed
go github.com/traefik/traefik/v2
<2.11.41
2.11.41
go github.com/traefik/traefik/v3
<3.6.11
>=3.7.0-ea.1, <3.7.0-ea.2
3.6.11
3.7.0-ea.2

Affected products

  • traefik traefik

Classification

Weakness
  • CWE-208 Observable Timing Discrepancy

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.