# FOSSBilling vulnerabilities & exploitation

> As of 2026-10-05, Threadlinqs tracks 9 FOSSBilling CVEs, 0 in the CISA Known Exploited Vulnerabilities catalog, linked to 0 tracked threat campaigns.

**Data as of:** 2026-10-05

## Exploitation timeline

Threadlinqs has recorded 9 FOSSBilling CVEs published between 2026-07-15 and 2026-07-15. The busiest month was 2026-07 (9 new CVEs). None of them is listed in CISA KEV yet.

## Most exploited vulnerabilities

Ranked with CISA KEV listings first, then EPSS exploit probability, then CVSS score. Showing 9 of 9 tracked FOSSBilling CVEs.

- [CVE-2026-53641](https://intel.threadlinqs.com/cve/CVE-2026-53641) — MEDIUM 4.8 · EPSS 0.3% · 2026-07-06
- [CVE-2026-43928](https://intel.threadlinqs.com/cve/CVE-2026-43928) — LOW 2.3 · EPSS 0.3% · 2026-07-06
- [CVE-2026-53644](https://intel.threadlinqs.com/cve/CVE-2026-53644) — HIGH 8.6 · EPSS 0.3% · 2026-07-06
- [CVE-2026-53645](https://intel.threadlinqs.com/cve/CVE-2026-53645) — HIGH 8.5 · EPSS 0.2% · 2026-07-06
- [CVE-2026-53643](https://intel.threadlinqs.com/cve/CVE-2026-53643) — HIGH 8.7 · EPSS 0.2% · 2026-07-06
- [CVE-2026-53642](https://intel.threadlinqs.com/cve/CVE-2026-53642) — MEDIUM 5.3 · EPSS 0.2% · 2026-07-06
- [CVE-2026-53640](https://intel.threadlinqs.com/cve/CVE-2026-53640) — LOW 2.3 · EPSS 0.2% · 2026-07-06
- [CVE-2026-43927](https://intel.threadlinqs.com/cve/CVE-2026-43927) — MEDIUM 6.9 · EPSS 0.2% · 2026-07-06
- [CVE-2026-53646](https://intel.threadlinqs.com/cve/CVE-2026-53646) — HIGH 7.7 · EPSS 0.2% · 2026-07-06

## Products affected

Threadlinqs normalises CPE and CNA product records across all 9 CVEs; 1 distinct FOSSBilling product is affected. The most frequently affected:

- FOSSBilling — 9 CVEs

## Threat activity

No tracked threat campaign references FOSSBilling products or CVEs yet. Vulnerability records are still monitored for exploitation and linked as campaigns are ingested.

## How to prioritise FOSSBilling patching

This order follows the data Threadlinqs holds for FOSSBilling, not a generic severity checklist:

- No FOSSBilling CVE is in CISA KEV yet, so rank by exploit probability instead.
- Outside KEV, the highest EPSS scores are [CVE-2026-53641](https://intel.threadlinqs.com/cve/CVE-2026-53641) (0.3%), [CVE-2026-43928](https://intel.threadlinqs.com/cve/CVE-2026-43928) (0.3%), [CVE-2026-53644](https://intel.threadlinqs.com/cve/CVE-2026-53644) (0.3%).
- 0 CVEs score Critical and 4 High on CVSS v3 (maximum 8.7, average 6.1); sequence these after KEV and high-EPSS items.

## About this data

Vendor attribution comes from the CNA and CPE product records of each CVE, folded to one vendor name; CVSS, EPSS and KEV status are read from the Threadlinqs CVE catalog; campaign and actor links come from tracked threat records. Counts reflect the data as of 2026-10-05 and refresh daily.

Canonical: https://intel.threadlinqs.com/vendors/fossbilling
All vendors: https://intel.threadlinqs.com/vendors
Full detection coverage and IOCs via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp