Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-63388
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-20 18:16:36 UTC
Updated2026-08-20 18:16:36 UTC
DescriptionLibevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Risk And Classification

Primary CVSS: v3.1 8.4 HIGH from [email protected]

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Problem Types: CWE-617 | CWE-787 | CWE-617 CWE-617: Reachable Assertion | CWE-787 CWE-787: Out-of-bounds Write

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.4HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED8.4HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Libevent Libevent affected < 2.1.13 Not specified
CNA Libevent Libevent affected >= 2.2.0-alpha, < 2.2.2-alpha Not specified

References

ReferenceSourceLinkTags
github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c968549... [email protected] github.com
github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f43... [email protected] github.com
github.com/libevent/libevent/releases/tag/release-2.1.13-stable [email protected] github.com
github.com/libevent/libevent/releases/tag/release-2.2.2-alpha [email protected] github.com
github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338 [email protected] github.com
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