Slack Nebula before 1.9.7 mishandles CIDR in some configurations and thus accepts arbitrary source IP addresses within the Nebula network.
https://github.com/slackhq/nebula/pull/1494
https://github.com/slackhq/nebula/pull/1493
Source: Mitre, NVD
Published: 2025-10-23
Updated: 2026-04-15
Base Score: 3.6
Vector: CVSS2#AV:N/AC:H/Au:S/C:N/I:P/A:P
Severity: Low
Base Score: 4.9
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L
Severity: Medium
EPSS: 0.00036