CVE-2026-53089 bpf: Fix use-after-free in offloaded map/prog info fill
A use-after-free vulnerability in the Linux kernel's BPF subsystem allows attackers to potentially execute code or escalate privileges during network namespace teardown.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53089?
CVE-2026-53089 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix use-after-free in offloaded map/prog info fill
When querying info for an offloaded BPF map or program, bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns() obtain the network namespace with get_net(dev_net(offmap->netdev)). However, the associated netdev's netns may be racing with teardown during netns destruction. If the netns refcount has already reached 0, get_net() performs a refcount_t increment on 0, triggering:
refcount_t: addition on 0; use-after-free.
Although rtnl_lock and bpf_devs_lock ensure the netdev pointer remains valid, they cannot prevent the netns refcount from reaching zero.
Fix this by using maybe_get_net() instead of get_net(). maybe_get_net() uses refcount_inc_not_zero() and returns NULL if the refcount is already zero, which causes ns_get_path_cb() to fail and the caller to return -ENOENT -- the correct behavior when the netns is being destroyed.
Weakness: CWE-416
Which versions are affected by CVE-2026-53089?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53089?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-53089 being exploited?
There is no known exploitation of CVE-2026-53089 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90300, BELL-CVE-2026-53089, DEBIAN-CVE-2026-53089, GHSA-fwh4-95hv-8xhf, ROOT-OS-DEBIAN-11-CVE-2026-53089, ROOT-OS-DEBIAN-12-CVE-2026-53089 and 4 more.