Vulnerability · Published Oct 23, 2025 · Assigned by mitre
CVE-2025-62820
Medium 4.9
In plain English
A medium-severity security flaw in Nebula from Slack. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.9Medium
Exploit odds (30 days)0.2%top 87.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Slack Nebula before 1.9.7 mishandles CIDR in some configurations and thus accepts arbitrary source IP addresses within the Nebula network.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/slackhq/nebula | 1.9.7 | GHSA-x6fh-7qmf-69xh |
| Go | github.com/slackhq/nebula | 1.9.7 | GO-2025-4068 |
Affected products (as reported)
Weakness: CWE-420 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L