CVE-2026-43030
Published: 01 May 2026
Summary
CVE-2026-43030 is a high-severity an unspecified weakness 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 3.6th 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 CM-6 (Configuration Settings) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-43030 is a vulnerability in the Linux kernel's BPF subsystem, specifically affecting the regsafe() function handling pointers to packets. Under the condition where the old register's range is BEYOND_PKT_END and the current register's range is N, regsafe() may incorrectly return true, preventing exploration of valid packet range states. This bug, published on 2026-05-01, carries a CVSS score of 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
A local attacker with low privileges can exploit this issue with low attack complexity and no user interaction. Exploitation involves loading a malicious BPF program that bypasses verification due to the faulty regsafe() logic, potentially achieving high impacts on confidentiality, integrity, and availability.
Mitigation patches are available in Linux kernel stable trees via the referenced commits: https://git.kernel.org/stable/c/015a74476dc1ab6923d89f1ee009aaf43faa7185, https://git.kernel.org/stable/c/37db6b9726d0bcf91cbdf9d63b558c50da49f968, https://git.kernel.org/stable/c/7241da033fdc507b920e092dab1f97b945cb0370, https://git.kernel.org/stable/c/8aebe18069394f4a79d2d82080a0f806da449996, and https://git.kernel.org/stable/c/a8502a79e832b861e99218cbd2d8f4312d62e225. Security practitioners should update affected kernel versions to incorporate these fixes.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26629
Vulnerability details
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix regsafe() for pointers to packet In case rold->reg->range == BEYOND_PKT_END && rcur->reg->range == N regsafe() may return true which may lead to current state with valid packet range…
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not being explored. Fix the bug.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The Linux kernel BPF verifier flaw directly enables local privilege escalation by allowing a low-privileged attacker to load a malicious BPF program that bypasses safety checks, leading to kernel-level code execution and high-impact compromise.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the BPF regsafe() verification bug by requiring timely application of vendor patches to vulnerable Linux kernel versions.
Enforces secure kernel configuration settings, such as kernel.unprivileged_bpf_disabled=1, to block low-privilege users from loading exploitable BPF programs.
Minimizes attack surface by disabling unnecessary BPF-related kernel functionalities, preventing exploitation opportunities for low-privilege local attackers.