CVE-2026-63495 (GCVE-0-2026-63495)

Vulnerability from cvelistv5 – Published: 2026-08-20 17:49 – Updated: 2026-08-20 19:17
VLAI
Title
Libevent: Unbounded memory accumulation in WebSocket server via fragmented frames
Summary
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.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:16 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Vendor Product Version
libevent libevent Affected: >= 2.2.0-alpha-dev, < 2.2.2-alpha
Create a notification for this product.
Show details on NVD website
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