CVE-2026-27638
Insecure Access Control in Actual Sync API Allows Data Manipulation
Publication date: 2026-02-26
Last updated on: 2026-02-27
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| actualbudget | actual | to 26.2.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-862 | The product does not perform an authorization check when an actor attempts to access a resource or perform an action. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects the Actual personal finance tool in its multi-user mode using OpenID. Before version 26.2.1, the sync API endpoints (those under `/sync/*`) did not verify whether the authenticated user actually owned or had access to the budget file they were trying to operate on.
As a result, any authenticated user could read, modify, or overwrite any other user's budget files simply by providing the file ID, without proper authorization checks.
This issue was fixed in version 26.2.1.
How can this vulnerability impact me? :
This vulnerability can lead to unauthorized access and modification of personal financial data stored in the Actual application.
An attacker who is authenticated can read sensitive budget files of other users, potentially exposing private financial information.
Additionally, the attacker can modify or overwrite other users' budget files, leading to data loss, corruption, or manipulation.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade the Actual personal finance tool to version 26.2.1 or later, which patches the issue.