CVE-2026-46716: Nezha Monitoring: RoleMember can run shell on every server (cross-tenant RCE) via POST /api/v1/cron

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.5%, percentile 41: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 41% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes github.com/nezhahq/nezha (Go) >= 1.4.0, < 1.14.15-0.20260517022419-d7526351cf97, fixed in 1.14.15-0.20260517022419-d7526351cf97. Check your lockfile, including transitive dependencies.

What it is

Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 1.4.0 to before version 2.0.8, a RoleMember user can create a scheduled cron task with Cover=CronCoverAll, Servers=[] and an arbitrary Command. At every tick of the scheduler, the dashboard pushes that command to every server in the global ServerShared map — including servers that belong to other tenants (admin's servers, other members' servers). Each agent runs the command and returns the output, which is then sent to the attacker's own NotificationGroup → attacker-controlled webhook. This issue has been patched in version 2.0.8.

From the GitHub advisory

Summary

nezha's dashboard supports two user roles: RoleAdmin (Role==0) and RoleMember (Role==1). The cron routes POST /api/v1/cron and PATCH /api/v1/cron/:id are wired through commonHandler (any authenticated user) rather than adminHandler, and the per-server permission check on cron creation has a vacuous-true bypass.

A RoleMember user can create a scheduled cron task with Cover=CronCoverAll, Servers=[] and an arbitrary Command. At every tick of the scheduler, the dashboard pushes that command to every server in the global ServerShared map — including servers that belong to other tenants (admin's servers, other members' servers). Each agent runs the command and returns the output, which is then sent to the attacker's own NotificationGroup → attacker-controlled webhook.

Net effect: any RoleMember (including a self-bound OAuth2 user, if the dashboard has OAuth2 configured) gets pre-validated cross-tenant RCE on every nezha-monitored host in the deployment.

Affected versions

Weakness type: CWE-78, CWE-269, CWE-862.

Product: github.com/nezhahq/nezha (Go) · Assigned by: GitHub_M · Published: 2026-06-12

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.49% probability of exploitation activity in the next 30 days; percentile 41.

Timeline

• 2026-05-23 — GitHub-reviewed advisory GHSA-99gv-2m7h-3hh9 published (critical)
• 2026-06-12 — CVE record published by GitHub_M
• 2026-06-15 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-99gv-2m7h-3hh9 github.com
2. CVE.org record CVE-2026-46716 cve.org
3. NVD entry CVE-2026-46716 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com

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