VDB
CVE-2026-63495
CVE-2026-63495
PUBLISHED
CVSS 7.5 HIGH
Reported by GitHub_M · Published August 20, 2026
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.
Risk Scores
CVSS 3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| libevent | libevent | >= 2.2.0-alpha-dev, < 2.2.2-alpha |
| libevent | libevent | 2.2.0-alpha-dev |
Timeline
- Aug 20, 2026 CVE Published
- Aug 22, 2026 Coalition ESS Score
- Aug 24, 2026 EPSS Score
- Aug 26, 2026 EPSS Score
- Aug 30, 2026 EPSS Score
- Sep 3, 2026 EPSS Score
- Sep 3, 2026 Security Advisory
- Sep 6, 2026 EPSS Score
- Sep 9, 2026 EPSS Score
- Sep 10, 2026 EPSS Score
- Sep 12, 2026 EPSS Score
- Sep 16, 2026 EPSS Score