CVE-2026-42154

Prometheus: remote read endpoint allows denial of service via crafted snappy payload

CVSS 3.1 7.5 HIGHEUVD CVSS 3.1 7.5 CVSS 3.1 · [email protected] · Secondary 7.5 HIGHCVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary 7.5 HIGHCVSS_V3 Publisher rating HIGHFixed by github.com/prometheus/prometheus 0.311.3 Fixed by github.com/prometheus/prometheus 0.305.2osv · severity unknownFixed by github.com/prometheus/prometheus 0.305.2 Fixed by github.com/prometheus/prometheus 0.311.3KEV status unknown

Original advisory

cve-program · CVE-2026-42154

Published

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.

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euvd · EUVD-2026-27091

Published

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nvd · CVE-2026-42154

Published

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osv · GHSA-8rm2-7qqf-34qm

Published

### Impact 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. ### Patches _Has the problem been patched? What versions should users upgrade to?_ Fixed in 3.11.3 and 3.5.3 LTS. Users should upgrade to these versions or later. ### Workarounds User who can not upgrade can place Prometheus behind a reverse proxy or firewall that requires authentication before requests reach /api/v1/read.

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osv · GO-2026-5264

Published

Prometheus: Remote read endpoint allows denial of service via crafted snappy payload in github.com/prometheus/prometheus

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Affected versions, risk and source history

Exploitation and risk

Source status

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Risk history

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Advisory history

14 saved versions

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13 Nov 2026 12:02:10 UTC