CVE-2026-63388

8.4 HIGH 0.1% exploit odds Fix listed Memory safety OS & kernel

What it is

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.

At a glance

Exploitability: Can be exploited locally on the machine without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.1% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-20 18:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-26 10:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.1% in the next 30 days (EPSS).
Severity: 8.4 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-08-20 18:16 UTC
Last modified: 2026-10-26 10:10 UTC
Exploit probability: 0.1% · EPSS, next 30 days
Weakness: CWE-617
Record status: Awaiting Analysis

Attack profile CVSS 3.1 · 8.4

Attack vector: Local
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-63388.md and follow it. Check whether this project is affected by CVE-2026-63388. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record