CVE-2026-119574

MEDIUM 5.9

Traefik 3.2.0 before 3.7.15 FastProxy Data Race Denial of Service

CVSS Score

5.9

EPSS Score

0.0%

EPSS Percentile

0th

Traefik from 3.2.0 before 3.7.15 contains a data race in the experimental FastProxy that allows unauthenticated attackers to crash the process by abusing HTTP/1 protocol upgrades. Attackers can repeatedly open and abort upgraded connections such as WebSocket, corrupting the unsynchronized shared bufio.Reader and triggering an unrecovered panic that terminates Traefik.

CWE	CWE-567
Vendor	traefik
Product	traefik
Published	Oct 30, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

traefik / traefik

3.2.0 < 3.7.15

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/traefik/traefik/security/advisories/GHSA-ww7c-q3mv-xx22 vulncheck.com: https://www.vulncheck.com/advisories/traefik-3.2.0-before-3.7.15-fastproxy-data-race-denial-of-service