Information Disclosure in @actual-app/sync-server (CVE-2026-57449)
Summary
Vulnerability in @actual-app/sync-server (CVE-2026-57449). Risk of unauthorized operations or information disclosure. Exploitable via GET /cors-proxy. Mitigation: upgrade to 26.7.0 or later.
Original description
The description as published by the source.
Summary
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 such as:
https://api.github.com/repos/acme/plugin-private/contents/.env
https://api.github.com/repos/acme/plugin-secrets/actions/secrets
https://api.github.com/repos/acme/plugin-internal/releases
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.
Affected Endpoint
GET /cors-proxy?url=...
This endpoint is mounted only when:
if (config.get('corsProxy.enabled')) {
app.use('/cors-proxy', corsApp.handlers);
}
Source: packages/sync-server/src/app.ts:68-70
Details
The CORS proxy is disabled by default but can be enabled through ACTUAL_CORS_PROXY_ENABLED. The GitHub token is configured through ACTUAL_GITHUB_TOKEN:
github: {
token: {…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-57449 has been found in @actual-app/sync-server.
Attackers can target a specific entry point like GET /cors-proxy over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade @actual-app/sync-server to 26.7.0 or later.
If unsure, ask your IT team or search "@actual-app/sync-server CVE-2026-57449" on the vendor's site.
CVE-2026-57449 (@actual-app/sync-server) — CWE-200
Attack surface: GET /cors-proxy / ACTUAL_GITHUB_TOKEN / ACTUAL_CORS_PROXY_ENABLED / api.github.com
Patched: 26.7.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) exists in @actual-app/sync-server. Attackers reach the vulnerable code path via GET /cors-proxy.
Check the vendor advisory for the affected versions of @actual-app/sync-server. Attack surface: GET /cors-proxy / ACTUAL_GITHUB_TOKEN / ACTUAL_CORS_PROXY_ENABLED / api.github.com.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 26.7.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /cors-proxy requests with malformed payloads or SQL meta-characters. Run grep -r '@actual-app/sync-server' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@actual-app/sync-server' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@actual-app/sync-serverを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /cors-proxy' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /cors-proxyへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade @actual-app/sync-server to 26.7.0ステージング環境で 26.7.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against GET /cors-proxy on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- web github.com
- web nvd.nist.gov
- web github.com