CyberSecBulletin
CVE-2026-53094NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-53094 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions a713b72ff88cdab4d5d692908ab1259ada511f4d, 25484c39d1ec82a0368798d956da3de5039b3fe8, 059525cf18e69a9313baf947d8898c6ee7ca6b65 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.13% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to a713b72ff88cdab4d5d692908ab1259ada511f4d or 25484c39d1ec82a0368798d956da3de5039b3fe8 or 059525cf18e69a9313baf947d8898c6ee7ca6b65 or c79f8503d83d4665be461fb9e45e215d0380c67b, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.141 or 6.12.91 or 6.18.33 or 7.0.10, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux2b3486bc2d237ec345b3942b7be5deabf8c8fed1 up to, but not including, a713b72ff88cdab4d5d692908ab1259ada511f4d; 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 up to, but not including, 25484c39d1ec82a0368798d956da3de5039b3fe8; 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 up to, but not including, 059525cf18e69a9313baf947d8898c6ee7ca6b65; 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 up to, but not including, c79f8503d83d4665be461fb9e45e215d0380c67b; 2b3486bc2d237ec345b3942b7be5deabf8c8fed1 up to, but not including, a1aa9ef47c299c5bbc30594d3c2f0589edf908e6; 6.3a713b72ff88cdab4d5d692908ab1259ada511f4d, 25484c39d1ec82a0368798d956da3de5039b3fe8, 059525cf18e69a9313baf947d8898c6ee7ca6b65, c79f8503d83d4665be461fb9e45e215d0380c67b, a1aa9ef47c299c5bbc30594d3c2f0589edf908e6
LinuxLinux Kernel6.3 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.106.6.141, 6.12.91, 6.18.33, 7.0.10

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stale offload->prog pointer after constant blinding When a dev-bound-only BPF program (BPF_F_XDP_DEV_BOUND_ONLY) undergoes JIT compilation with constant blinding enabled (bpf_jit_harden >= 2), bpf_jit_blind_constants() clones the program. The original prog is then freed in bpf_jit_prog_release_other(), which updates aux->prog to point to the surviving clone, but fails to update offload->prog. This leaves offload->prog pointing to the freed original program. When the network namespace is subsequently destroyed, cleanup_net() triggers bpf_dev_bound_netdev_unregister(), which iterates ondev->progs and calls __bpf_prog_offload_destroy(offload->prog). Accessing the freed prog causes a page fault: BUG: unable to handle page fault for address: ffffc900085f1038 Workqueue: netns cleanup_net RIP: 0010:__bpf_prog_offload_destroy+0xc/0x80 Call Trace: __bpf_offload_dev_netdev_unregister+0x257/0x350 bpf_dev_bound_netdev_unregister+0x4a/0x90 unregister_netdevice_many_notify+0x2a2/0x660 ... cleanup_net+0x21a/0x320 The test sequence that triggers this reliably is: 1. Set net.core.bpf_jit_harden=2 (echo 2 > /proc/sys/net/core/bpf_jit_harden) 2. Run xdp_metadata selftest, which creates a dev-bound-only XDP program on a veth inside a netns (./test_progs -t xdp_metadata) 3. cleanup_net -> page fault in __bpf_prog_offload_destroy Dev-bound-only programs are unique in that they have an offload structure but go through the normal JIT path instead of bpf_prog_offload_compile(). This means they are subject to constant blinding's prog clone-and-replace, while also having offload->prog that must stay in sync. Fix this by updating offload->prog in bpf_jit_prog_release_other(), alongside the existing aux->prog update. Both are back-pointers to the prog that must be kept in sync when the prog is replaced.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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