CVE-2026-75501
CVE-2026-75501 is a Missing Authentication vulnerability. O3 Security confirms whether CVE-2026-75501 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
A vulnerability in the Calix EXOS firmware for the GS7 XGS (GS5239XG) residential router allows unauthenticated remote attackers to modify NAT port‑forwarding rules via the UPnP WANIPConnection…
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-75501.
Description
A vulnerability in the Calix EXOS firmware for the GS7 XGS (GS5239XG) residential router allows unauthenticated remote attackers to modify NAT port‑forwarding rules via the UPnP WANIPConnection service. The device exposes the MiniUPnPd control endpoint on the WAN interface on TCP port 5000 without access controls. A remote attacker can send crafted SOAP requests to add, delete, or enumerate port mappings, or to query the external IP address, without authentication. Successful exploitation may enable bypass of the firewall/NAT boundary and exposure of internal LAN services to the public internet.
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-2026-75501 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-2026-75501 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-2026-75501. 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-2026-75501 in your dependencies?
O3 detects CVE-2026-75501 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.