Actual has an OpenID `client_secret` Disclosure via Broken Authorization Guard in `/openid/config`
CVE-2026-42604

6.9MEDIUM

Key Information:

Vendor

Actualbudget

Status
Actual
Vendor
CVE Published:
12 June 2026

What is CVE-2026-42604?

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.

Affected Version(s)

actual < 26.5.0

References

https://github.com/actualbudget/actual/security/advisorie...
x_refsource_CONFIRM
https://actualbudget.org/blog/release-26.5.0
x_refsource_MISC

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
High
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.