Description
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Published: 2026-08-20
Score: 5.8 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Thu, 20 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Description Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Title Libevent: Dangling Pointer in `evbuffer_add_buffer_reference`
Weaknesses CWE-908
References
Metrics cvssV4_0

{'score': 5.8, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N'}

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-20T17:50:09.322Z

Reserved: 2026-07-16T17:39:30.171Z

Link: CVE-2026-63381

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-20T18:16:35.530

Modified: 2026-08-20T18:16:35.530

Link: CVE-2026-63381

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-908

    Use of Uninitialized Resource