Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Prometheus | Prometheus | < 3.5.3 |
Related Weaknesses (CWE)
References
- https://github.com/prometheus/prometheus/pull/18584Issue TrackingPatch
- https://github.com/prometheus/prometheus/pull/18585Issue TrackingPatch
- https://github.com/prometheus/prometheus/releases/tag/v3.11.3Release Notes
- https://github.com/prometheus/prometheus/releases/tag/v3.5.3Release Notes
- https://github.com/prometheus/prometheus/security/advisories/GHSA-8rm2-7qqf-34qmVendor Advisory
FAQ
What is CVE-2026-42154?
CVE-2026-42154 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ...
How severe is CVE-2026-42154?
CVE-2026-42154 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-42154?
Check the references section above for vendor advisories and patch information. Affected products include: Prometheus Prometheus.