Out-of-bounds read in libevent - #VU136944
Published: July 6, 2026
Vulnerability identifier: #VU136944
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in decode_tag_internal() when parsing a malformed fragmented evbuffer tag. A remote attacker can send specially crafted input with more than 5 continuation bytes to cause a denial of service.
The issue is reachable through evtag_unmarshal_header(), and potential higher-level reachability exists via evrpc request parsing.
Affected software
libevent
Remediation
Install security update from vendor's website.
libevent - update to 2.1.13