Vulnerability in Traefik
CVE-2026-119574
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/traefik/traefik/security/advisories/GHSA-ww7c-q3mv-xx22 (vendor-advisory)
- www.vulncheck.com/advisories/traefik-3.2.0-before-3.7.15-fastproxy-data-race-de… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-119574?
- CVE-2026-119574 is a medium-severity vulnerability in Traefik, classified under CWE-567. CVSS score: 5.9/10. Published 2026-10-30.
- How severe is CVE-2026-119574?
- Medium severity. CVSS v3 base score is 5.9 out of 10.