High · published May 4, 2026
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.
| Product | Versions | Fixed in |
|---|---|---|
| prometheus/prometheus | < 3.5.3 | 3.5.3 |
| prometheus/prometheus | ≥ 3.6.0, < 3.11.3 | 3.11.3 |