CVE-2026-43056
Published: 01 May 2026
Summary
CVE-2026-43056 is a high-severity Use After Free (CWE-416) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 3.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SI-11 (Error Handling).
Deeper analysis
CVE-2026-43056 is a use-after-free vulnerability in the Linux kernel's mana network driver, affecting the add_adev() function in its error path. If auxiliary_device_add() fails, the function jumps to the add_fail label and calls auxiliary_device_uninit(adev). This invokes the adev_release() callback, which frees the containing struct mana_adev since adev is embedded within it. The code then falls through to the init_fail label and accesses adev->id, resulting in a use-after-free condition. The vulnerability was published on 2026-05-01.
The CVSS v3.1 base score is 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating it requires local access, low attack complexity, and low privileges. A local attacker with basic user privileges can exploit this during device initialization errors in the mana driver, potentially achieving high impacts on confidentiality, integrity, and availability, such as arbitrary code execution or kernel crashes.
Mitigation requires updating to patched Linux kernel versions incorporating the fixes from the referenced stable commits, including 43f5b19fd190fea20d052bc84741b28031d5baa9, 5f4061f8225d18695e5afe9bbf1cb7bd673d7872, c4ea7d8907cf72b259bf70bd8c2e791e1c4ff70f, d88541ffd56d62a61e77209080001eddd4d69815, and e5a75bf026c686b91a7dc6f9c5caf5016745d1fe. These patches save the auxiliary device ID in a local variable before auxiliary_device_add() and use it in the cleanup path after auxiliary_device_uninit() to prevent the use-after-free.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26655
Vulnerability details
In the Linux kernel, the following vulnerability has been resolved: net: mana: fix use-after-free in add_adev() error path If auxiliary_device_add() fails, add_adev() jumps to add_fail and calls auxiliary_device_uninit(adev). The auxiliary device has its release callback set to adev_release(), which frees…
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the containing struct mana_adev. Since adev is embedded in struct mana_adev, the subsequent fall-through to init_fail and access to adev->id may result in a use-after-free. Fix this by saving the allocated auxiliary device id in a local variable before calling auxiliary_device_add(), and use that saved id in the cleanup path after auxiliary_device_uninit().
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local use-after-free in Linux kernel driver enables exploitation for privilege escalation (arbitrary kernel code execution) and endpoint DoS (kernel crashes).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the use-after-free vulnerability by requiring timely patching of the Linux kernel's mana driver with the specific commits that fix the add_adev() error path.
Addresses the root cause of improper error handling in the auxiliary_device_add() failure path that leads to freeing and subsequent access of the mana_adev structure.
Mitigates exploitation of the use-after-free in the kernel by enforcing memory protections such as KASLR and guard pages that hinder arbitrary code execution or crashes.