CVE-2026-101087 Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6
Authenticated users can bypass SSRF denylists via IPv6 transition ranges to access restricted internal endpoints in Nezha.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-101087?
CVE-2026-101087 is a medium-severity server-side request forgery vulnerability in nezhahq nezha, published on 27 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Nezha versions 2.0.10 through 2.3.2 use a restricted HTTP client to validate user-configurable notification and DDNS webhook URLs, but the denylist did not cover IPv6 transition ranges — specifically the 6to4 prefix 2002::/16 and the local-use IPv4/IPv6 translation prefix 64:ff9b:1::/48. Because such addresses satisfy Go's netip.Addr.IsGlobalUnicast check, the URL validator accepted them. An authenticated user able to configure a webhook may be able to cause the dashboard to issue requests to an otherwise restricted IPv6 endpoint, but only where the dashboard's network provides unusual or non-standards-compliant routing for these transition ranges; no direct path to an IPv4 metadata, loopback, or private-network HTTP request has been demonstrated. The issue is fixed in version 2.3.3 (commit d1fcde8e), which blocks both prefixes.
Weakness: CWE-918
Which versions are affected by CVE-2026-101087?
How do I fix CVE-2026-101087?
No fix has been published for CVE-2026-101087 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-101087 being exploited?
There is no known exploitation of CVE-2026-101087 in the wild and no public exploit code.
Sources
Also known as GHSA-jr2j-7hvh-h4q9, GHSA-qvpf-fj3j-7cw6.