Nezha Monitoring: Stored future DDNS profile ID allows unauthorized use of another user's DDNS profile context

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L

EPSS

• CVE-2026-53521: 0.27% estimated exploitation activity in the next 30 days; percentile 19.85 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary PATCH /server/{id} accepts and persists nonexistent ddnsprofiles IDs for a member-owned server. If another user later creates a DDNS profile with one of those IDs, the DDNS worker resolves the stored ID and dispatches an update using the other user's DDNS profile configuration in the context of the attacker's server. This is a second-order authorization bypass: direct binding to an existing foreign DDNS profile is correctly denied, but an unresolved future ID can be stored first and later becomes a live cross-user reference. Affected versions Confirmed on: - Nezha v2.0.14 - Commit: 8b5e382fe217107c7b777ea9c6b4bc3d2e156202 The exact affected version range was not determined. Impact A normal member who owns a server can prebind one or more future DDNS profile IDs to that server. If another user later creates a DDNS profile with a matching ID, the dashboard DDNS worker can use the victim's DDNS profile/provider configuration for the attacker's server. In the validated worker…

Published by the source

26 Jun 2026, 23:02 UTC

Last modified by the source

26 Jun 2026, 23:02 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-39g2-8x68-pmx8

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# Patch Next advisory brief: CVE-2026-53521

Advisory: Nezha Monitoring: Stored future DDNS profile ID allows unauthorized use of another user's DDNS profile context
IDs: CVE-2026-53521, GHSA-39g2-8x68-pmx8
Record: https://patchnext.com/advisories/cve-2026-53521 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/nezhahq/nezha 2.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/nezhahq/nezha: affected >= 2.0.14, < 2.1.0; fixed in 2.1.0

## Suggested inspection (read-only)
- Go github.com/nezhahq/nezha: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/nezhahq/nezha.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-39g2-8x68-pmx8 (GitHub-reviewed advisory GHSA-39g2-8x68-pmx8 lists affected ranges: Go github.com/nezhahq/nezha >=2.0.14 <2.1.0)

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