SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-29622

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.

MEDIUM 6.1EPSS 19.6%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 19.6%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

Description

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.

CVSS 3.1
6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
19.56% probability · 97th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-601
Affected
prometheus/prometheus
Source
security-advisories@github.com
EPSS trend
0%10%20%26 October 2026: 19.56%26 October 202626 October 2026

EPSS 19.6% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.