CVE-2026-114640: Traefik from v3.7.0 before v3.7.14 contains an authentication bypass vulnerability in its Kubernetes Ingress-N

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HIGH 8.7REMOTEWATCHLISTUPGRADE

CVE-2026-114640 is a high-severity flaw (CVSS 8.7) affecting traefik. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Traefik from v3.7.0 before v3.7.14 contains an authentication bypass vulnerability in its Kubernetes Ingress-NGINX provider that forwards client-supplied Ssl-Client-* headers on the plaintext HTTP router. When ssl-redirect is disabled alongside auth-tls-pass-certificate-to-upstream, unauthenticated attackers can send Ssl-Client-Verify: SUCCESS with a chosen certificate subject and issuer to impersonate mTLS identities.

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.7 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-290
Published	2026-10-22
Last modified	2026-10-27

Publisher (CNA): VulnCheck · Vendor: traefik

Last updated 2026-10-27 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-22 02:16 UTCPublished CVE record published
2026-10-27 14:16 UTCUpdated Record last modified

traefik traefik UPGRADE

Affected: >= 3.7.0 and < 3.7.14

Fixed in: 3.7.14

Safe to downgrade to: a release before 3.7.0

1. Check installed version

apt-cache policy traefik || rpm -q traefik || traefik --version

2. UPGRADE to 3.7.14 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade traefik

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade traefik

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.7.0 (Debian / Ubuntu)

apt-cache madison traefik sudo apt install traefik=<VERSION_BEFORE_3.7.0> sudo apt-mark hold traefik

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list traefik sudo dnf downgrade traefik-<VERSION_BEFORE_3.7.0> sudo dnf versionlock add traefik

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-114640?

traefik: upgrade to 3.7.14. Exact commands for each OS are on this page.

Is CVE-2026-114640 being exploited?

CVE-2026-114640 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-114640 affect?

CVE-2026-114640 affects traefik. Severity is high (CVSS 8.7). Traefik from v3.7.0 before v3.7.14 contains an authentication bypass vulnerability in its Kubernetes Ingress-NGINX provider that forwards client-supplied Ssl-Client-* headers on the plaintext HTTP router. When ssl-redirect is disabled along

How urgent is CVE-2026-114640?

Priority 43/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

nginx vulnerabilities · Kubernetes vulnerabilities · Traefik vulnerabilities

Related CVEs

CVE-2026-114635 HIGH 8.7 UPGRADE Traefik before v2.11.58 and v3.7.14 contains an authentication bypass vulnerability in its SNI check, which is
CVE-2026-114636 HIGH 8.7 DOWNGRADE Traefik v3.7.13 before v3.7.14 contains an access-control bypass in the Kubernetes Ingress NGINX provider, whe
CVE-2026-114637 HIGH 8.7 UPGRADE Traefik from v3.2.0 before v3.7.14 contains an authentication bypass vulnerability in the experimental FastPro
CVE-2026-114638 HIGH 8.7 UPGRADE Traefik v3.7.0 before v3.7.14 contains an improper authentication vulnerability in the Kubernetes Ingress NGIN
CVE-2026-114639 HIGH 8.7 UPGRADE Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first reques

References

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