CVE-2021-34813
CVSS v3
9.8
CRITICAL
EPSS Score
4.3 %
exploit probability, as of 2026-10-18
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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Affected and fixed versions
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
- CVE-2021-34813 Red Hat Product Security
libolm: allows a malicious Matrix homeserver to crash a client
Description
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.
Technical details
- Published
- 2021-06-16
Frequently asked questions
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