cve.bz

CVE-2021-34813

9.8 criticalEPSS 4.3%

Critical (9.8) in matrix olm. EPSS 4.3% chance of exploitation in the next 30 days.

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.

Severity

CVSS 3.1

9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
4.3% chance of exploitation in the next 30 days; higher than 91% of CVEs (scores of 2026-10-31)
CWE
CWE-787
Published
Modified
Record from
the NVD, synced

Affected

References

Check your stackJSON