CVE-2026-90707 is a high-severity (CVSS 8.3) Buffer Overflow vulnerability in open5gs open5gs. O3 Security detects and blocks CVE-2026-90707 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
A security flaw has been discovered in Open5GS up to 2.7.x. Affected is the function amf_nnrf_try_old_amf_discovery_fallback of the file src/amf/nnrf-handler.c of the component Old…
Description
A security flaw has been discovered in Open5GS up to 2.7.x. Affected is the function amf_nnrf_try_old_amf_discovery_fallback of the file src/amf/nnrf-handler.c of the component Old AMF Discovery Fallback. The manipulation of the argument discovery_option results in use after free. The attack may be performed from remote. The patch is identified as ddd683a35f8aaac2b7b9884a24cd53bddfc65238. Applying a patch is advised to resolve this issue.
Affected Products
open5gsopen5gsDetection & mitigation playbook
Vendor / applianceDetect
Inventory every open5gs open5gs deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2026-90707 yet — track the open5gs open5gs advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-90707 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-90707. 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-2026-90707 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-90707 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.