CVE-2026-49397: Nezha Monitoring Information Disclosure in Service Endpoints

CVE-2026-49397 · Severity: medium · CVSS 5.3 · Published 2026-06-12

Nezha Monitoring is a tool used by administrators to track the health and performance of servers and websites. A security flaw allows unauthorized users to discover "private" services that were intended to be hidden from the public dashboard. By accessing specific web addresses, an attacker can see the names and performance data of these internal services, potentially revealing sensitive information about a company's internal infrastructure.

Technologies: github.com/nezhahq/nezha (Go), NezhaHQ Nezha. Vendors: Go, NezhaHQ.

Quick answers

Is CVE-2026-49397 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-49397 being exploited in the wild.
How severe is CVE-2026-49397?
Medium severity, with a CVSS score of 5.3, published 12 June 2026.
Which products and versions are affected?
github.com/nezhahq/nezha (Go) >= 2.0.0, < 2.0.14, SEMVER:introduced=0, SEMVER:introduced=2.0.0,fixed=2.0.14; NezhaHQ Nezha >= 2.0.0, < 2.0.14; NezhaHQ Nezha Monitoring >= 2.0.0, < 2.0.14.
Is there a fix for CVE-2026-49397?
Yes. github.com/nezhahq/nezha (Go): upgrade to 2.0.14 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-49397 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-49397?
Check whether you run github.com/nezhahq/nezha (Go), NezhaHQ Nezha or NezhaHQ Nezha Monitoring at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/nezhahq/nezha (Go): upgrade to 2.0.14 or later
    go get github.com/nezhahq/nezha@v2.0.14

Technical details

An information disclosure vulnerability exists in Nezha Monitoring due to inconsistent authorization checks across API endpoints. While the main service-listing endpoint correctly filters services marked with 'EnableShowInService: false', the 'listServerServices' and 'getServiceHistory' endpoints utilize raw data accessors that bypass this visibility flag. An unauthenticated attacker can perform a linear scan of server or service IDs to retrieve the names and performance metrics of private services. This occurs because the 'optionalAuth' group allows guest access, and the backend fails to re-verify the visibility status before emitting service identity data. The issue is addressed in version 2.0.14.

Affected products

  • nezhahq Nezha Monitoring >= 2.0.0, < 2.0.14

Identifiers

  • CVE-2026-49397
  • GHSA-vrmh-5mmx-hjwx
  • GO-2026-5672

Timeline

  • 2026-05-26: advisory: GitHub Security Advisory published
  • 2026-06-12: disclosed: CVE published to NVD
  • 2026-06-12: patched: Fix released in version 2.0.14

References

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