Resource exhaustion in Traefik - CVE-2026-26999
Published: May 5, 2026
Vulnerability identifier: #VU129665
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-26999
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Containous
Affected software:
Traefik
Traefik
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in the TCP router TLS handshake handling in (*Router).ServeTCP when processing TLS connections on TCP routers. A remote attacker can send an incomplete TLS record and stop further data transmission to cause a denial of service.
By opening many stalled connections in parallel, file descriptors and goroutines can be exhausted, degrading availability of services on the affected entrypoint.
How to mitigate CVE-2026-26999
Install security update from vendor's website.