Answer in brief
CVE-2026-63388 records a High severity (CVSS 8.4) vulnerability in Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept. The current sources do not mark it as known exploited. The current feed maps libevent/libevent (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps libevent/libevent (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| libevent/libeventgeneric | <2.1.13 || >=2.2.0-alpha <2.2.2-alpha | 2.1.13, 2.2.2-alpha |
Published upstream
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 20, 2026
Libevent 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.
Quoted source text, attributed separately from HOL analysis.