Summary
OneUptime has authorization bypass via client‑controlled is-multi-tenant-query header that leads to cross‑tenant data exposure and account takeover
Impact
This vulnerability allows a low‑privileged authenticated user to:
- bypass tenant isolation
- access other tenant projects
- read sensitive user credential fields
- leak plaintext reset tokens
- reset victim passwords
- fully take over victim accounts
Because OneUptime is a multi‑tenant monitoring platform, this allows attackers to compromise any tenant account in the system.
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
CVE-2026-30956 has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.0.21); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-30956? CVE-2026-30956 is a critical-severity missing authorization vulnerability in @oneuptime/common (npm), affecting versions < 10.0.21. It is fixed in 10.0.21. The application does not perform an authorization check before performing a sensitive operation.
- How severe is CVE-2026-30956? CVE-2026-30956 has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of @oneuptime/common are affected by CVE-2026-30956? @oneuptime/common (npm) versions < 10.0.21 is affected.
- Is there a fix for CVE-2026-30956? Yes. CVE-2026-30956 is fixed in 10.0.21. Upgrade to this version or later.
- Is CVE-2026-30956 exploitable, and should I be worried? Whether CVE-2026-30956 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-30956 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-30956? Upgrade
@oneuptime/commonto 10.0.21 or later.