CVE-2026-27604
FOSSBilling is a free, open-source billing and client management system. Starting in version 0.5.4 and prior to version 0.8.0, an authorization bypass in the API role handling allows…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
FOSSBilling is a free, open-source billing and client management system. Starting in version 0.5.4 and prior to version 0.8.0, an authorization bypass in the API role handling allows unauthenticated access to privileged /api/system/* endpoints. Because system resolves to the cron admin identity, attackers can invoke admin API methods without valid credentials, session, or CSRF token. Version 0.8.0 patches the issue. Some workarounds are available. Block external access to /api/system/* at reverse proxy/WAF, restrict API access by trusted source IPs only (api.allowed_ips), rotate all admin/client API tokens immediately, invalidate active sessions and reset high-privilege credentials, and/or review API request logs for suspicious /api/system/ access and treat as potential incident.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-27604 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-27604 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-27604. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-27604 in your dependencies?
O3 detects CVE-2026-27604 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.