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.
Metrics
Affected Vendors & Products
References
History
Wed, 30 Sep 2026 15:30:00 +0000
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ssvc
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Sun, 27 Sep 2026 23:15:00 +0000
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| First Time appeared |
Nezhahq
Nezhahq nezha |
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| Vendors & Products |
Nezhahq
Nezhahq nezha |
Sun, 27 Sep 2026 21:00:00 +0000
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| 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. | |
| Title | Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6 | |
| Weaknesses | CWE-918 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: VulnCheck
Published: 2026-09-27T20:49:58.749Z
Updated: 2026-09-30T14:12:28.088Z
Reserved: 2026-09-27T20:29:07.432Z
Link: CVE-2026-101087
Updated: 2026-09-30T14:12:24.875Z
Status : Deferred
Published: 2026-09-27T21:17:02.587
Modified: 2026-09-30T15:22:18.827
Link: CVE-2026-101087
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