CVE-2026-103472

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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 38% of CVEs (scores of 2026-10-25)

CWE

CWE-770

Published

2026-09-30

Modified

2026-10-01

Record from

the NVD, synced 2026-10-19

References

• https://github.com/Corvusoft/restbed
• https://github.com/Corvusoft/restbed/blob/e1227a297ce6d4e9f78222456507b29bb8ab77e9/src/corvusoft/restbed/detail/web_socket_impl.cpp#L117
• https://github.com/Corvusoft/restbed/issues/558
• https://www.vulncheck.com/advisories/restbed-through-5.0.0-websocket-memory-exhaustion-via-unbounded-frame-buffering

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