CVE-2026-23383
What it is
In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing struct bpf_plt contains a u64 target field. Currently, the BPF JIT allocator requests an alignment of 4 bytes (sizeof(u32)) for the JIT buffer. Because the base address of the JIT buffer can be 4-byte aligned (e.g., ending in 0x4 or 0xc), the relative padding logic in build_plt() fails to ensure that target lands on an 8-byte boundary. This leads to two issues: 1. UBSAN reports misaligned-access warnings when dereferencing the structure. 2. More critically, target is updated concurrently via WRITE_ONCE() in bpf_arch_text_poke() while the JIT'd code executes ldr. On arm64, 64-bit loads/stores are only guaranteed to be single-copy atomic if they are 64-bit aligned. A misaligned target risks a torn read, causing the JIT to jump to a corrupted address. Fix this by increasing the allocation alignment requirement to 8 bytes (sizeof(u64)) in bpf_jit_binary_pack_alloc(). This anchors the base of the JIT buffer to an 8-byte boundary, allowing the relative padding math in build_plt() to correctly align the target field.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel < 6.12.77
- Linux Kernel < 6.18.17
- Linux Kernel < 6.19.7
- Linux Kernel 6.0
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-23383.md and follow it. Check whether this project is affected by CVE-2026-23383. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/519b1ad91de5bf7a496f2b858e9212db6328e1de
- https://git.kernel.org/stable/c/66959ed481a474eaae278c7f6860a2a9b188a4d6
- https://git.kernel.org/stable/c/80ad264da02cc4aee718e799c2b79f0f834673dc
- https://git.kernel.org/stable/c/ef06fd16d48704eac868441d98d4ef083d8f3d07
References
- https://git.kernel.org/stable/c/519b1ad91de5bf7a496f2b858e9212db6328e1de
- https://git.kernel.org/stable/c/66959ed481a474eaae278c7f6860a2a9b188a4d6
- https://git.kernel.org/stable/c/80ad264da02cc4aee718e799c2b79f0f834673dc
- https://git.kernel.org/stable/c/ef06fd16d48704eac868441d98d4ef083d8f3d07
- https://git.kernel.org/stable/c/f5a41b61b5faae1965a5a2cb55322fe8f17e3b2d
- https://git.kernel.org/stable/c/fcb9c6275f712860c22c96a472b73d05cabb75cd