CVE-2026-107909
Pre-authentication heap out-of-bounds write in FalkorDB Bolt WebSocket frame handling via unbounded payload length
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.
INFO
Published Date :
Oct. 9, 2026, 6:17 a.m.
Last Modified :
Oct. 9, 2026, 6:17 a.m.
Remotely Exploit :
No
Source :
33c584b5-0579-4c06-b2a0-8d8329fcab9c
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | ||||
| CVSS 4.0 | HIGH | 33c584b5-0579-4c06-b2a0-8d8329fcab9c |
Solution
- Update FalkorDB to version 4.20.0 or later.
- Ensure the Bolt endpoint is disabled if not in use.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-107909.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-107909 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-107909
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-107909 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-107909 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 33c584b5-0579-4c06-b2a0-8d8329fcab9c
Oct. 09, 2026
Action Type Old Value New Value 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H Added CWE CWE-787 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/107xxx/CVE-2026-107909.json">CVE-2026-107909</a> Added Reference https://github.com/FalkorDB/FalkorDB/commit/0b11a00b34b25c4d4fdfe55f0a35c8a00593bd7d Added Reference https://github.com/FalkorDB/FalkorDB/pull/2170 Added Reference https://github.com/FalkorDB/FalkorDB/releases/tag/v4.20.0