Auth bypass in Actualbudget Actual
CVE-2026-27638
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (27.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.003 · change: -0.000
Affected products
- Actualbudget Actual — versions < 26.2.1
Weakness classification (CWE)
References
- github.com/actualbudget/actual/security/advisories/GHSA-qmjj-p7m9-wjrv (Exploit, Vendor Advisory)
- github.com/actualbudget/actual/commit/9966c024cb75f57943193cac8e42f401efed9d08 (Patch)
- github.com/actualbudget/actual/releases/tag/v26.2.1 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-27638?
- CVE-2026-27638 is a high-severity vulnerability in Actualbudget Actual, classified under Missing Authorization. CVSS score: 7.1/10. Published 2026-02-26.
- How severe is CVE-2026-27638?
- High severity. CVSS v3 base score is 7.1 out of 10.