Summary
OneUptime's GitHub App callback trusts attacker-controlled state and installation_id values and updates Project.gitHubAppInstallationId with isRoot: true without validating that the caller is authorized for the target project. This allows an attacker to overwrite another project's GitHub App installation binding.
Related GitHub endpoints also lack effective authorization, so a valid installation ID can be used to enumerate repositories and create CodeRepository records in an arbitrary project.
Details
The callback decodes unsigned base64 JSON from state and uses the embedded projectId directly:
It then writes the supplied installation_id into the target project with root privileges:
await ProjectService.updateOneById({
id: new ObjectID(projectId),
data: { gitHubAppInstallationId: installationId },
props: { isRoot: true },
});
The userId in state is only checked for presence, not authenticity:
The install flow also generates state as plain base64 JSON, not a signed or session-bound token:
The follow-on endpoints are also vulnerable:
- Repository listing: https://github.com/OneUptime/oneuptime/blob/master/Common/Server/API/GitHubAPI.ts#L179-L258
- Repository connect: https://github.com/OneUptime/oneuptime/blob/master/Common/Server/API/GitHubAPI.ts#L260-L356
- Middleware allows requests with no token to continue as
Public: https://github.com/OneUptime/oneuptime/blob/master/Common/Server/Middleware/UserAuthorization.ts#L205-L211 - Installation tokens are minted from any valid installation ID: https://github.com/OneUptime/oneuptime/blob/master/Common/Server/Utils/CodeRepository/GitHub/GitHub.ts#L347-L425
PoC
Minimal proof of unauthorized project tampering:
STATE=$(printf '%s' '{"projectId":"<victim-project-uuid>","userId":"x"}' | base64 | tr -d '\n')
curl -isk "https://<host>/api/github/auth/callback?installation_id=999999999&state=${STATE}"
Expected result:
- Server returns a
302redirect to/dashboard/<victim-project-uuid>/code-repository?installation_id=999999999 - The target project's
gitHubAppInstallationIdis overwritten
Impact
- Unauthorized modification of
Project.gitHubAppInstallationId - Temporary GitHub integration breakage if a bogus installation ID is set
- Cross-project binding of attacker-controlled GitHub App installations
- Repository metadata disclosure for a supplied valid installation ID
- Unauthorized creation of
CodeRepositoryrecords in arbitrary projects
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
CVE-2026-30920 has a CVSS score of 8.6 (High). The vector is network-reachable, no 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 (10.0.19); 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-2026-30920? CVE-2026-30920 is a high-severity missing authorization vulnerability in @oneuptime/common (npm), affecting versions < 10.0.19. It is fixed in 10.0.19. The application does not perform an authorization check before performing a sensitive operation.
- How severe is CVE-2026-30920? CVE-2026-30920 has a CVSS score of 8.6 (High). 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-2026-30920? @oneuptime/common (npm) versions < 10.0.19 is affected.
- Is there a fix for CVE-2026-30920? Yes. CVE-2026-30920 is fixed in 10.0.19. Upgrade to this version or later.
- Is CVE-2026-30920 exploitable, and should I be worried? Whether CVE-2026-30920 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-2026-30920 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-2026-30920? Upgrade
@oneuptime/commonto 10.0.19 or later.