Missing Release of Resource after Effective Lifetime Affecting github.com/traefik/traefik/pkg/server/router/tcp package, versions <2.11.38>=3.0.0-beta1 <3.6.9
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMTRAEFIKTRAEFIKPKGSERVERROUTERTCP-15435560
- published6 Mar 2026
- disclosed5 Mar 2026
- creditOleh Konko
Introduced: 5 Mar 2026
CVE-2026-26999 Â (opens in a new tab)How to fix?
Upgrade github.com/traefik/traefik/pkg/server/router/tcp to version 2.11.38, 3.6.9 or higher.
Overview
Affected versions of this package are vulnerable to Missing Release of Resource after Effective Lifetime due to incomplete handling of the errors in TLS handshake. An attacker can cause the service to become unavailable by initiating multiple incomplete TLS handshakes, leading to resource exhaustion.
PoC
There is a potential vulnerability in Traefik managing TLS handshake on TCP routers.
When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthenticated client can exploit this by sending an incomplete TLS record and stopping further data transmission, causing the TLS handshake to stall indefinitely and holding connections open.
By opening many such stalled connections in parallel, an attacker can exhaust file descriptors and goroutines, degrading availability of all services on the affected entrypoint.