CVE-2021-32813: medium-severity vulnerability in traefik
Drop Headers via Malicious Connection Header
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.8epss 1.1%
Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of them sets a request header, then sending a request with a certain Connection header will cause it to be removed before the request is sent. In this case, the backend does not see the request header. A patch is available in version 2.4.13. There are no known workarounds aside from upgrading.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected products
traefik · traefikRelated CVEs — traefik
In the same product, most dangerous first.
CVE-2026-85595CRITICALTraefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuthEPSS 2.5%CVE-2022-23632HIGHTraefik skips the router TLS configuration when the host header is an FQDNEPSS 1.7%CVE-2024-45410CRITICALHTTP client can remove the X-Forwarded headers in TraefikEPSS 1.5%CVE-2025-54386HIGHTraefik's Client Plugin is Vulnerable to Path Traversal, Arbitrary File Overwrites and Remote Code ExecutionEPSS 1.4%CVE-2022-39271HIGHTraefik HTTP/2 connections management could cause a denial of serviceEPSS 1.4%CVE-2023-47633HIGHUncontrolled Resource Consumption in TraefikEPSS 1.3%