A heap-based out-of-bounds write in the ws_read_frame function (src/bolt/ws.c) and the buffer_apply_mask function (src/bolt/buffer.c) in FalkorDB before 4.20.0 allows a remote unauthenticated attacker to cause a denial of service and possibly corrupt heap memory by sending a WebSocket frame with a 64-bit extended payload length to the Bolt port. The payload length is not bounded, and the only bounds check in buffer_apply_mask is an ASSERT(), which is compiled out in release builds, so the function XORs memory beyond the end of the receive buffer with the attacker-supplied mask key. Only deployments that enable the Bolt endpoint (BOLT_PORT, disabled by default) are affected.
History

Thu, 15 Oct 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 09 Oct 2026 05:30:00 +0000

Type Values Removed Values Added
Description A heap-based out-of-bounds write in the ws_read_frame function (src/bolt/ws.c) and the buffer_apply_mask function (src/bolt/buffer.c) in FalkorDB before 4.20.0 allows a remote unauthenticated attacker to cause a denial of service and possibly corrupt heap memory by sending a WebSocket frame with a 64-bit extended payload length to the Bolt port. The payload length is not bounded, and the only bounds check in buffer_apply_mask is an ASSERT(), which is compiled out in release builds, so the function XORs memory beyond the end of the receive buffer with the attacker-supplied mask key. Only deployments that enable the Bolt endpoint (BOLT_PORT, disabled by default) are affected.
Title Pre-authentication heap out-of-bounds write in FalkorDB Bolt WebSocket frame handling via unbounded payload length
First Time appeared Falkordb
Falkordb falkordb
Weaknesses CWE-787
CPEs cpe:2.3:a:falkordb:falkordb:*:*:*:*:*:*:*:*
Vendors & Products Falkordb
Falkordb falkordb
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H'}

cvssV4_0

{'score': 8.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: securin

Published: 2026-10-09T05:08:12.082Z

Updated: 2026-10-15T15:54:47.531Z

Reserved: 2026-10-09T04:54:48.677Z

Link: CVE-2026-107909

cve-icon Vulnrichment

Updated: 2026-10-15T15:53:58.108Z

cve-icon NVD

Status : Deferred

Published: 2026-10-09T06:17:12.303

Modified: 2026-10-15T16:17:35.393

Link: CVE-2026-107909

cve-icon Redhat

No data.