CVE-2026-42154 HIGH

CVE-2026-42154: Prometheus: remote read endpoint allows denial of service via crafted snappy payload

Vendor Prometheus
Product prometheus
Weakness CWE-400
Published May 4, 2026
Last update June 30, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 4, 2026 CVE published
June 30, 2026 Record updated