Answer in brief
CVE-2026-107909 records a High severity (CVSS 8.8) vulnerability in Pre-authentication heap out-of-bounds write in FalkorDB Bolt WebSocket frame handling via unbounded payload length. The current sources do not mark it as known exploited. The current feed maps FalkorDB/FalkorDB (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps FalkorDB/FalkorDB (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| FalkorDB/FalkorDBgeneric | >=0 <4.20.0 | 4.20.0 |
Published upstream
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 9, 2026
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.
Quoted source text, attributed separately from HOL analysis.