CVE-2026-42604 PUBLISHED

Actual has an OpenID `client_secret` Disclosure via Broken Authorization Guard in `/openid/config`

Assigner: GitHub_M
Reserved: 29.04.2026 Published: 12.06.2026 Updated: 12.06.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U
CVSS Score: 6.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	actualbudget
Product	actual
Versions	Version < 26.5.0 is affected

References

Problem Types

CWE-863: Incorrect Authorization CWE