CVE-2026-42154 | Prometheus: remote read endpoint allows denial of service via crafted snappy payload

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.

Published: 2026-05-04 Last update: 2026-05-11 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42154 is rated Low Risk (32/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42154

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42154

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-42154

GitHub Security Advisory for CVE-2026-42154

GHSA-8rm2-7qqf-34qm · Severity: high · Ecosystem: go — Prometheus: Remote read endpoint allows denial of service via crafted snappy payload

OS Trackers for CVE-2026-42154

vendor priority summary link
debian not yet assigned CVE-2026-42154 not yet assigned priority: Debian including 1 source packages (prometheus), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-42154
suse high CVE-2026-42154 severity important: SUSE including 1 source package names (golang-github-prometheus-prometheus-3.11.3-1.1), 1 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 1. https://www.suse.com/security/cve/CVE-2026-42154/
ubuntu medium CVE-2026-42154 medium priority: Ubuntu including 1 source packages (prometheus), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 8. https://ubuntu.com/security/CVE-2026-42154

Affected software / configurations for CVE-2026-42154

Vendor Product Version Raw CPE
prometheus prometheus < 3.5.3 cpe:2.3:a:prometheus:prometheus:*:*:*:*:*:*:*:*
prometheus prometheus >= 3.6.0, < 3.11.3 cpe:2.3:a:prometheus:prometheus:*:*:*:*:*:*:*:*

References for CVE-2026-42154

cvelogic Threat Intelligence