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Vulnerability details: VCID-eejx-9f6j-9qej
Vulnerability ID VCID-eejx-9f6j-9qej
Aliases CVE-2021-34813
Summary Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while it is attempting to retrieve an Olm encrypted room key backup from the homeserver) because olm_pk_decrypt has a stack-based buffer overflow. Remote code execution might be possible for some nonstandard build configurations.
Status Published
Exploitability 0.5
Weighted Severity 2.7
Risk 1.4
Affected and Fixed Packages Package Details
Weaknesses (0)
There are no known CWE.
System Score Found at
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
epss 0.04458 https://api.first.org/data/v1/epss?cve=CVE-2021-34813
archlinux Low https://security.archlinux.org/AVG-2077
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-34813
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-34813
989997 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=989997
AVG-2077 https://security.archlinux.org/AVG-2077
USN-USN-5194-1 https://usn.ubuntu.com/USN-5194-1/
No exploits are available.
Exploit Prediction Scoring System (EPSS)
Percentile 0.8902
EPSS Score 0.04458
Published At April 1, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T16:34:55.126676+00:00 Debian Oval Importer Import https://www.debian.org/security/oval/oval-definitions-bullseye.xml.bz2 38.0.0