Description
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Published: 2026-08-20
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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History

Thu, 27 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important


Fri, 21 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
First Time appeared Libevent Project
Libevent Project libevent
Vendors & Products Libevent Project
Libevent Project libevent

Thu, 20 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


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 an incorrect integer conversion in event_tagging.c when evtag_unmarshal_header uses evtag_decode_int to decode an attacker-controlled uint32 payload length and returns it as a signed int. Values above INT_MAX become negative or truncated, and evtag_unmarshal_string can use the converted value in allocation sizing, producing a wrapped large allocation request and denial of service. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Title Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.
Weaknesses CWE-190
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Libevent Project Libevent
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-20T19:50:32.085Z

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

Link: CVE-2026-63384

cve-icon Vulnrichment

Updated: 2026-08-20T19:50:27.744Z

cve-icon NVD

Status : Received

Published: 2026-08-20T18:16:36.367

Modified: 2026-08-20T20:17:45.193

Link: CVE-2026-63384

cve-icon Redhat

Severity : Important

Publid Date: 2026-08-20T17:53:08Z

Links: CVE-2026-63384 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T13:01:07Z

Weaknesses