What’s Vulnerable › Vulnerabilities

CVE-2026-27638: ActualBudget missing authorization in sync endpoints allows cross-user budget file access in multi-user mode

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-02-26 · updated 2026-06-17
• Weakness: CWE-862

Description

Actual is a local-first personal finance tool. Prior to version 26.2.1, in multi-user mode (OpenID), the sync API endpoints (`/sync/*`) don't verify that the authenticated user owns or has access to the file being operated on. Any authenticated user can read, modify, and overwrite any other user's budget files by providing their file ID. Version 26.2.1 patches the issue.

Affected products

• actualbudget actual: before 26.2.1 — fixed in 26.2.1

How to fix

Upgrade to a fixed version: actualbudget actual 26.2.1. Check the vendor advisory for mitigations.

References

• https://github.com/actualbudget/actual/commit/9966c024cb75f57943193cac8e42f401efed9d08
• https://github.com/actualbudget/actual/releases/tag/v26.2.1
• https://github.com/actualbudget/actual/security/advisories/GHSA-qmjj-p7m9-wjrv

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