CVE intelligence and bounded remediation

CVE-2026-27638 — Actual is a local-first personal finance tool

High CVSS 7.1

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.

Severity
High
CVSS
7.1 (3.1)
Published
2026-02-26
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-862

Affected products

  • actualbudget / actual

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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