CVE-2026-42154

high

Description

Prometheus is an open-source monitoring system and time series database. Prior to versions 3.5.3 and 3.11.3, the remote read endpoint (/api/v1/read) does not validate the declared decoded length in a snappy-compressed request body before allocating memory. An unauthenticated attacker can send a small payload that causes a huge heap allocation per request. Under concurrent load this can exhaust available memory and crash the Prometheus process. This issue has been patched in versions 3.5.3 and 3.11.3.

References

https://github.com/prometheus/prometheus/security/advisories/GHSA-8rm2-7qqf-34qm

https://github.com/prometheus/prometheus/releases/tag/v3.5.3

https://github.com/prometheus/prometheus/releases/tag/v3.11.3

https://github.com/prometheus/prometheus/pull/18585

https://github.com/prometheus/prometheus/pull/18584

Details

Source: Mitre, NVD

Published: 2026-05-04

Updated: 2026-05-04

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High