Is CVE-2026-114637 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-114637 being exploited in the wild.

How severe is CVE-2026-114637?

High severity, with a CVSS score of 8.7, published 22 October 2026.

Which products and versions are affected?

Traefik Labs Traefik v3.2.0 through v3.7.13.

How is CVE-2026-114637 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-114637?

Check whether you run Traefik Labs Traefik at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-114637: Traefik FastProxy NTLM/Negotiate authentication bypass in connection pool

CVE-2026-114637 · Severity: high · CVSS 8.7 · Published 2026-10-22

Traefik is a reverse proxy and load balancer used to route and manage traffic to backend services. An experimental FastProxy feature fails to properly isolate authenticated connections, allowing unauthenticated users to be served previously-authenticated backend connections. An attacker can impersonate a legitimate user and access their data or perform actions on their behalf without providing credentials.

Technologies: Traefik Labs Traefik. Vendors: Traefik Labs.

Quick answers

Is CVE-2026-114637 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-114637 being exploited in the wild.
How severe is CVE-2026-114637?: High severity, with a CVSS score of 8.7, published 22 October 2026.
Which products and versions are affected?: Traefik Labs Traefik v3.2.0 through v3.7.13.
Is there a fix for CVE-2026-114637?: Yes: fixed in v3.7.14. Until then: Disable the experimental.fastProxy feature until upgrading to v3.7.14 or later. Users on v3.2 through v3.6 (no longer maintained) must upgrade to v3.7.14 as no backported patches are available for those versions. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-114637 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-114637?: Check whether you run Traefik Labs Traefik at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: v3.7.14

Disable the experimental.fastProxy feature until upgrading to v3.7.14 or later. Users on v3.2 through v3.6 (no longer maintained) must upgrade to v3.7.14 as no backported patches are available for those versions.

Technical details

The vulnerability exists in Traefik's experimental FastProxy connection pool implementation, which does not properly pin NTLM/Negotiate-authenticated backend connections to individual frontend connections. When experimental.fastProxy is enabled with plain HTTP backends using connection-bound NTLM or Negotiate authentication, an unauthenticated client on a new frontend connection can receive a pooled backend connection where a victim has already completed authentication, bypassing credential requirements.

Affected products

Traefik Labs Traefik v3.2.0 through v3.7.13

Timeline

2026-10-07: disclosed
2026-10-21: advisory
2026-10-22: patched

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.