CVE-2021-29622: Prometheus

Medium severity, CVSS 6.1. EPSS: 19.6% chance of exploitation in the next 30 days.

Prometheus is an open-source monitoring system and time series database. In 2.23.0, Prometheus changed its default UI to the New ui. To ensure a seamless transition, the URL's prefixed by /new redirect to /. Due to a bug in the code, it is possible for an attacker to craft an URL that can redirect to any other URL, in the /new endpoint. If a user visits a prometheus server with a specially crafted address, they can be redirected to an arbitrary URL. The issue was patched in the 2.26.1 and 2.27.1 releases. In 2.28.0, the /new endpoint will be removed completely. The workaround is to disable access to /new via a reverse proxy in front of Prometheus.

Affected products

• Prometheus Prometheus: from 2.23.0, before 2.26.1 (fixed in 2.26.1); version 2.27.0 only

Published 2021-05-19. Last modified 2026-06-17.