CVE-2026-114637: Traefik from v3.2.0 before v3.7.14 contains an authentication bypass vulnerability in the experimental FastPro

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HIGH 8.7REMOTEUPGRADE

CVE-2026-114637 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 v3.2.0 before v3.7.14 contains an authentication bypass vulnerability in the experimental FastProxy connection pool, which fails to pin NTLM/Negotiate-authenticated backend connections to their frontend connection. Unauthenticated clients can be handed a pooled keep-alive backend connection where a victim completed an NTLM or Negotiate handshake, letting them read victim data and act as that victim.

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 78%)
CISA exploited list	No
Weakness	CWE-488
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: >= 3.2.0 and < 3.7.14

Fixed in: 3.7.14

Safe to downgrade to: a release before 3.2.0

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 3.2.0 (Debian / Ubuntu)

apt-cache madison traefik sudo apt install traefik=<VERSION_BEFORE_3.2.0> 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_3.2.0> 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-2026-114637?

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

Is CVE-2026-114637 being exploited?

CVE-2026-114637 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-2026-114637 affect?

CVE-2026-114637 affects traefik. Severity is high (CVSS 8.7). Traefik from v3.2.0 before v3.7.14 contains an authentication bypass vulnerability in the experimental FastProxy connection pool, which fails to pin NTLM/Negotiate-authenticated backend connections to their frontend connection. Unauthentica

How urgent is CVE-2026-114637?

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

Software pages

Traefik vulnerabilities

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References

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