Actual is a local-first personal finance tool. Prior to 26.7.0, Actual Sync Server's CORS proxy is intended to let authenticated users fetch resources only from repositories listed in the official plugin allowlist. When `ACTUAL_GITHUB_TOKEN` is configured, the proxy automatically attaches the server's GitHub token to GitHub requests. The GitHub API allowlist check uses a raw `startsWith()` prefix test for `/repos/{owner}/{repo}` without requiring a path boundary after the repository name. If an allowlisted public plugin repository is `https://github.com/acme/plugin`, the proxy also accepts GitHub API URLs. Those URLs are outside the allowlisted repository but still pass because their API path starts with `/repos/acme/plugin`. The proxy then forwards the request with the server's `ACTUAL_GITHUB_TOKEN`, allowing any authenticated Actual user to read private GitHub resources reachable by that token. Version 26.7.0 fixes the issue.
Metrics
Affected Vendors & Products
References
History
Mon, 28 Sep 2026 13:30:00 +0000
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ssvc
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Sat, 26 Sep 2026 08:15:00 +0000
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Fri, 25 Sep 2026 22:30:00 +0000
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| Description | Actual is a local-first personal finance tool. Prior to 26.7.0, Actual Sync Server's CORS proxy is intended to let authenticated users fetch resources only from repositories listed in the official plugin allowlist. When `ACTUAL_GITHUB_TOKEN` is configured, the proxy automatically attaches the server's GitHub token to GitHub requests. The GitHub API allowlist check uses a raw `startsWith()` prefix test for `/repos/{owner}/{repo}` without requiring a path boundary after the repository name. If an allowlisted public plugin repository is `https://github.com/acme/plugin`, the proxy also accepts GitHub API URLs. Those URLs are outside the allowlisted repository but still pass because their API path starts with `/repos/acme/plugin`. The proxy then forwards the request with the server's `ACTUAL_GITHUB_TOKEN`, allowing any authenticated Actual user to read private GitHub resources reachable by that token. Version 26.7.0 fixes the issue. | |
| Title | Actual Sync Server: CORS Proxy GitHub API Allowlist Prefix Bypass Leaks Private Repositories Through the Server GitHub Token | |
| Weaknesses | CWE-200 CWE-284 CWE-863 |
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| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-09-25T22:10:39.706Z
Updated: 2026-09-28T13:07:46.380Z
Reserved: 2026-06-24T13:21:20.730Z
Link: CVE-2026-57449
Updated: 2026-09-28T13:07:39.869Z
Status : Deferred
Published: 2026-09-25T23:16:53.990
Modified: 2026-09-28T14:17:16.140
Link: CVE-2026-57449
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