6.9
MEDIUM CVSS 4.0
CVE-2026-42604
Actual has an OpenID `client_secret` Disclosure via Broken Authorization Guard in `/openid/config`
Description

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 `client_secret`—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.

INFO

Published Date :

June 12, 2026, 8:16 p.m.

Last Modified :

June 12, 2026, 8:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-42604 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Actualbudget actual
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Update Actual Budget sync-server to version 26.5.0 or later to fix information disclosure.
  • Update Actual Budget sync-server to version 26.5.0.
  • Apply security patches provided by the vendor.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-42604.

URL Resource
https://actualbudget.org/blog/release-26.5.0
https://github.com/actualbudget/actual/security/advisories/GHSA-49v6-pqjq-xw55
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-42604 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-42604 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-42604 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-42604 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jun. 12, 2026

    Action Type Old Value New Value
    Added Description 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 `client_secret`—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.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-863
    Added Reference https://actualbudget.org/blog/release-26.5.0
    Added Reference https://github.com/actualbudget/actual/security/advisories/GHSA-49v6-pqjq-xw55
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.