VULNERABILITY INTELLIGENCE
CVE-2026-63495
CVSS score7.5 HIGH
EPSS probability0.61%
CISA KEVNot currently listed
Published2026-08-20
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
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.
Weakness classification
- CWE-400: Uncontrolled Resource Consumption
- CWE-770: Allocation of Resources Without Limits or Throttling