CVE-2026-42154 — Prometheus: remote read endpoint allows denial of service via crafted snappy payload
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 declar…
Published: 2026-05-04 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7