Loading vulnerability…
CVE-2026-27604 is a critical authorization bypass in FOSSBilling affecting versions starting in 0.5.4 and before 0.8.0. The flaw is in API role validation, specifically the isRoleAllowed() logic in src/modules/Api/Controller/Client.php, where an exception for an invalid API role was created but not thrown due to a missing throw statement. FOSSBilling routes API requests as /api/:role/:module/:method and exposes roles including guest, client, admin, and system. In vulnerable versions, the system role resolves to the privileged cron admin identity (ROLE_CRON). Because invalid role handling failed open, unauthenticated remote attackers could access privileged /api/system/* endpoints and invoke administrative API methods without valid credentials, an authenticated session, or a CSRF token.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
4 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An authentication bypass in FOSSBilling caused by a missing throw statement in the API role checker, allowing unauthenticated attackers to access privileged /api/system/ endpoints and invoke admin functionality.
An authorization bypass vulnerability in FOSSBilling API role handling that allows unauthenticated attackers to access privileged admin `/api/system/*` endpoints by resolving `system` to the cron admin identity.
An authentication bypass in FOSSBilling caused by a missing throw keyword in API role validation, allowing unauthenticated access to privileged /api/system/ endpoints and enabling full compromise when chained with CVE-2026-28496.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.