Pre-authentication heap out-of-bounds write in FalkorDB Bolt WebSocket frame handling via unbounded payload length
Summary
| CVE | CVE-2026-107909 |
|---|---|
| State | PUBLISHED |
| Assigner | securin |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-09 06:17:12 UTC |
| Updated | 2026-10-09 06:17:12 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 8.8 HIGH from 33c584b5-0579-4c06-b2a0-8d8329fcab9c
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-787 | CWE-787 CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | Secondary | 8.8 | HIGH | 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/E:X/C... |
| 4.0 | CNA | CVSS | 8.8 | HIGH | 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 |
| 3.1 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | Secondary | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |
| 3.1 | CNA | CVSS | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H |
CVSS v4.0 Breakdown
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/FalkorDB/FalkorDB/pull/2170 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | github.com | |
| github.com/FalkorDB/FalkorDB/releases/tag/v4.20.0 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | github.com | |
| github.com/FalkorDB/FalkorDB/commit/0b11a00b34b25c4d4fdfe55f0a35c8a00593... | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Arjun Basnet from Securin (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-06-29T00:00:00.000Z | Reported to FalkorDB |
| CNA | 2026-06-29T00:00:00.000Z | Vendor acknowledged the report |
| CNA | 2026-07-08T00:00:00.000Z | Vendor removed Bolt protocol support (PR #2170) |
| CNA | 2026-07-13T00:00:00.000Z | FalkorDB 4.20.0 released without Bolt support |
| CNA | 2026-09-27T00:00:00.000Z | Coordinated disclosure period ended |
Solutions
CNA: 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.
Workarounds
CNA: 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.