restbed through 5.0.0 WebSocket Memory Exhaustion via Unbounded Frame Buffering

Advisories

restbed through 5.0.0 WebSocket Memory Exhaustion via Unbounded Frame Buffering

severity: high
date: 9/30/2026
Affecting: restbed <= 5.0.0
CVE: CVE-2026-103472
CWE: CWE-770 Allocation of Resources Without Limits or Throttling
CVSS: 8.7
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References: GitHub Issue #558
https://github.com/Corvusoft/restbed
https://github.com/Corvusoft/restbed/blob/e1227a297ce6d4e9f78222456507b29bb8ab77e9/src/corvusoft/restbed/detail/web_socket_impl.cpp#L117
Credit: MJ DHURGESH
Description: restbed through 5.0.0 accepts WebSocket frames with declared payload lengths up to 2^63 bytes and buffers the payload without size limits in an unbounded stream buffer. Remote unauthenticated attackers can declare large frame sizes and stream payload data to exhaust server memory, causing denial of service through process crash.

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