n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a NoSQL injection vulnerability in the MongoDB Chat Memory node that fails to validate the sessionId parameter. Unauthenticated attackers can supply MongoDB query operators in the sessionId field to access conversation histories from other users and perform unauthorized write and delete operations.
https://github.com/n8n-io/n8n/security/advisories/GHSA-w24g-6454-7w7f
Published: 2026-10-01
Updated: 2026-10-06
Base Score: 6.6
Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:P/A:P
Severity: Medium
Base Score: 8.1
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L
Severity: High
Base Score: 7
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:H/SI:L/SA:L
Severity: High
EPSS: 0.00201