CVE-2026-114639: Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first reques

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HIGH 8.7REMOTEUPGRADE

CVE-2026-114639 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 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first request preauthenticated with an Authorization: Negotiate token authenticates a socket in the globally shared backend connection pool, which is never isolated. Unauthenticated attackers on separate frontend connections can be assigned that NTLM/Kerberos-bound socket and perform reads or writes with the victim's identity.

Why this priority

High severity
Remotely exploitable, no login, no user action

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	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-287
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 14:17 UTCUpdated Record last modified

traefik traefik UPGRADE

Affected: >= 2.11.0 and < 2.11.58 · >= 3.0.0 and < 3.7.14

Fixed in: 2.11.58, 3.7.14

Safe to downgrade to: a release before 2.11.0

1. Check installed version

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

2. UPGRADE to 2.11.58 (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 2.11.0 (Debian / Ubuntu)

apt-cache madison traefik sudo apt install traefik=<VERSION_BEFORE_2.11.0> 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_2.11.0> 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-2026-114639?

traefik: upgrade to 2.11.58, 3.7.14. Exact commands for each OS are on this page.

Is CVE-2026-114639 being exploited?

CVE-2026-114639 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-2026-114639 affect?

CVE-2026-114639 affects traefik. Severity is high (CVSS 8.7). Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first request preauthenticated with an Authorization: Negotiate token authenticates a socket in the globally shared backend connection pool, w

How urgent is CVE-2026-114639?

Priority 41/100. High severity; Remotely exploitable, no login, no user action

Software pages

Traefik vulnerabilities

Related CVEs

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References

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