CVE-2026-42154
HIGHDescription
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.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 42% of all known CVEs.
References
- https://github.com/prometheus/prometheus/pull/18584
- https://github.com/prometheus/prometheus/pull/18585
- https://github.com/prometheus/prometheus/releases/tag/v3.11.3
- https://github.com/prometheus/prometheus/releases/tag/v3.5.3
- https://github.com/prometheus/prometheus/security/advisories/GHSA-8rm2-7qqf-34qm
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-11.