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.
Affected products
prometheus: prometheus
References10
- github.com/prometheus/prometheus/security/advisories/GHSA-8rm2-… Vendor Advisory
- github.com/prometheus/prometheus/pull/18584 Issue TrackingPatch
- github.com/prometheus/prometheus/pull/18585 Issue TrackingPatch
- github.com/prometheus/prometheus/releases/tag/v3.11.3 Release Notes
- github.com/prometheus/prometheus/releases/tag/v3.5.3 Release Notes
- access.redhat.com/errata/RHSA-2026:25039
- access.redhat.com/errata/RHSA-2026:25245
- access.redhat.com/errata/RHSA-2026:29770
- access.redhat.com/errata/RHSA-2026:30651
- access.redhat.com/errata/RHSA-2026:34357
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 58 · as of 13 November 2026
- CWE
- CWE-400CWE-789CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.