CVE-2026-63495

Published: Ago 20, 2026 Last Modified: Ago 20, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,5
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high

Description

AI Translation Available

Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws->incomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha.

400

Uncontrolled Resource Consumption

Draft
Common Consequences
Security Scopes Affected:
Availability Access Control Other
Potential Impacts:
Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other) Bypass Protection Mechanism Other
Applicable Platforms
Technologies: Not Technology-Specific, AI/ML
View CWE Details
770

Allocation of Resources Without Limits or Throttling

Incomplete
Common Consequences
Security Scopes Affected:
Availability
Potential Impacts:
Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other)
Applicable Platforms
All platforms may be affected
View CWE Details
https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx
https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c09…
https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha
https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx