Bug 2466505 (CVE-2026-42154)

Summary: CVE-2026-42154 github.com/prometheus/prometheus: Prometheus: Denial of Service via uncontrolled memory allocation in remote read endpoint
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akoudelk, alcohan, amctagga, anjoseph, anpicker, aoconnor, bdettelb, bniver, bparees, dfreiber, doconnor, drow, eborisov, eglynn, flucifre, gmeno, gparvin, groman, hasun, jbalunas, jburrell, jcantril, jfula, jjoyce, jkoehler, jowilson, jprabhak, jpretori, jschluet, lball, lbragsta, lchilton, lhh, lphiri, mbenjamin, mburns, mgarciac, mhackett, ngough, nyancey, ometelka, pahickey, ptisnovs, rhaigner, rhel-process-autobot, rojacob, sfeifer, sostapov, syedriko, vereddy, veshanka, vkumar, watson-tool-maintainers, wenshen, wtam, xdharmai, xiyuan
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Prometheus. An unauthenticated attacker can exploit the remote read endpoint (`/api/v1/read`) by sending a specially crafted, small snappy-compressed payload. This payload causes a disproportionately large memory allocation, leading to memory exhaustion and a Denial of Service (DoS) by crashing the Prometheus process.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2481305, 2488937, 2488939, 2488940, 2488941, 2481306, 2481307    
Bug Blocks:    

Description OSIDB Bzimport 2026-05-04 19:02:42 UTC 
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.
Comment 3 errata-xmlrpc 2026-07-01 18:36:05 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:34357 https://access.redhat.com/errata/RHSA-2026:34357
Comment 4 errata-xmlrpc 2026-07-01 19:20:59 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:34359 https://access.redhat.com/errata/RHSA-2026:34359
Comment 8 errata-xmlrpc 2026-07-08 15:50:48 UTC 
This issue has been addressed in the following products:

  RHEM 1.0 for RHEL 9

Via RHSA-2026:36796 https://access.redhat.com/errata/RHSA-2026:36796
Comment 9 errata-xmlrpc 2026-07-16 14:32:27 UTC 
This issue has been addressed in the following products:

  RHEM 1.1 for RHEL 10
  RHEM 1.1 for RHEL 9

Via RHSA-2026:41019 https://access.redhat.com/errata/RHSA-2026:41019