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Fencer Intel
medium 6.9

CVE-2026-42604 json

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

published 4mo ago modified 14d ago also EUVD-2026-36543

cvss
6.9
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

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.

Patch / fix

  • actualbudget actual 26.5.0

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
4mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 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
CNA 4.0 6.9 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/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

Affected products

  • actualbudget actual

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.