What is CVE-2026-53644?
FOSSBilling is a free, open-source billing and client management system. Versions 0.5.3 through 0.7.2 allow authenticated clients to both read and reset API key service secrets for orders that are no longer in an `active` state (e.g., `suspended`, `canceled`). The root cause is missing order-state validation in two client API endpoints, despite an `isActive()` helper already existing in the `Serviceapikey` module and the frontend UI correctly gating access on `order.status == 'active'`. Version 0.8.0 contains a fix. Some workarounds are available. If the `Serviceapikey` module is not needed, uninstall it to remove the affected endpoints. One may also use a reverse proxy or WAF to restrict access to `/api/client/order/service` and `/api/client/serviceapikey/reset` based on application-level order-state logic.
The record classifies CVE-2026-53644 under weakness class CWE-639. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 91 days ago.
Severity and exploitation probability
- CVSS v4.0 base score
- 8.6 — High (derived from score)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - EPSS (FIRST)
- 0.2% probability of exploitation in the next 30 days, higher than 16.3% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-06, last modified 2026-07-07
Is CVE-2026-53644 being exploited?
It currently carries a trending score of 34 in the Threadlinqs vulnerability feed.
Affected products and versions
- FOSSBilling: FOSSBilling
How to fix CVE-2026-53644
No vendor patch reference has been recorded for CVE-2026-53644 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-53644
No threat campaign in the Threadlinqs corpus currently references CVE-2026-53644, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.