CVE-2026-107909

Pre-authentication heap out-of-bounds write in FalkorDB Bolt WebSocket frame handling via unbounded payload length

Published Oct 9, 2026 CVSS 4.0 · 8.8 High EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Solution

Upgrade FalkorDB to version 4.20.0 or later. Bolt protocol support, including the code affected by this issue, was removed in 4.20.0.


Vendor Workaround

Leave the Bolt endpoint disabled (do not set the BOLT_PORT module configuration; it is disabled by default), or restrict network access to the Bolt port to trusted clients.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
securin
Published
Updated
Oct 15, 2026, 3:54 PM
Reserved
Oct 9, 2026, 4:54 AM
Status
Deferred
Published
Oct 9, 2026, 6:17 AM
Modified
Oct 15, 2026, 4:17 PM