CVE-2026-88012
Description
A flaw was found in Traefik, an open-source HTTP reverse proxy and load balancer. Its HTTP/3 entrypoints do not correctly apply read timeouts, which are intended to prevent prolonged connections. An unauthenticated client can exploit this by sending a slow request body, continuously trickling data. This allows the client to hold open a request and an upstream connection indefinitely, potentially exhausting backend connection pools and leading to a Denial of Service (DoS).
Statement
A flaw in Traefik's HTTP/3 implementation allows unauthenticated remote attackers to cause a denial of service against upstream services. Traefik fails to enforce read timeouts (respondingTimeouts.readTimeout) on HTTP/3 entrypoints due to missing QUIC stream deadline enforcement. An attacker can transmit slow request bodies to hold HTTP/3 connections open indefinitely, consuming available proxy resources and exhausting backend connection pools under default operational limits.
Mitigation
Disable HTTP/3 on Traefik entrypoints handling client traffic, or enforce strict request timeout controls at the upstream server/backend level until updated packages are deployed.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
