CVE-2026-63384

Libevent: `evtag_unmarshal_header()` decodes a wire `uint32` length into a signed `int` return value.

HIGH
8.7
CVSS Score
Published: August 20, 2026 at 05:53 PM UTC
Updated: October 26, 2026 at 10:10 AM UTC
1 product affected across 1 vendorLibevent

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Severity
HIGH8.7
Exploit prediction
EPSS 0.5%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Affected range stops below 2.1.13, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.2.2-alpha, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHGitHub_M
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-190

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