CVE-2026-53157
HIGHIn the Linux kernel, the following vulnerability has been resolved: net: phonet: free phonet_device after RCU grace period phonet_device_destroy() removes a phonet_device from the…
Description
In the Linux kernel, the following vulnerability has been resolved:
net: phonet: free phonet_device after RCU grace period
phonet_device_destroy() removes a phonet_device from the per-net device list with list_del_rcu(), but frees it immediately. RCU readers walking the same list can still hold a pointer to the object after it has been removed, leading to a slab-use-after-free.
Use kfree_rcu(), matching the lifetime rule already used by phonet_address_del() for the same object type.
Affected Products
linux kernellinuxDetection & mitigation playbook
Vendor / applianceDetect
Inventory every linux linux kernel 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 exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the linux linux kernel security patch or hotfix for CVE-2026-53157 on the affected version, following the vendor advisory for your exact build.
Workarounds
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-2026-53157 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-2026-53157. 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-2026-53157 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-53157 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.