High [CVE-2026-63384] Denial of Service via integer conversion error in `evtag_unmarshal_header`
This high-severity Red Hat Linux advisory covers CVE-2026-63384 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7.
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Summary
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. A flaw was found in Libevent.
An incorrect integer conversion in the `evtag_unmarshal_header` function allows a remote attacker to provide a specially crafted payload length. This can lead to a wrapped large allocation request, resulting in a denial of service (DoS) for the affected system.
Red Hat severity: Important — CVSS 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-190.
Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat Hardened Images; Red Hat OpenShift Container Platform 4. Red Hat does not currently list a fixing RHSA for this CVE.
Affected products named by the advisory: Red Hat package: libevent2.
- < 2.1.13
- < 2.2.2-alpha
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
- 2.1.13
- 2.2.2
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Mitigation
Upgrade to a fixed release: 2.1.13, 2.2.2. That is the remediation for this advisory.
The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
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