---
id: CVE-2026-53036
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf, arm64: Fix off-by-one in check_imm signed range check

  check_imm(bits, imm) is used in the arm64 BPF JIT to verify that
  a branch displacement (in arm64 instruction…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf, arm64: Fix off-by-one in check_imm signed range check

  check_imm(bits, imm) is used in the arm64 BPF JIT to verify that
  a branch displacement (in arm64 instruction…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
published: '2026-06-24'
updated: '2026-07-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53036'
references:
  - url: 'https://git.kernel.org/stable/c/1a113b5497297871699cd498b1b83542e0db7f15'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1dd8be4ec722ce54e4cace59f3a4ba658111b3ec'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6927f0d6794aa73318bbfa929f1ff6065b0620df'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7fd3b41260c6120e7b60164afea5d961af6224f9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a5dfeb3b61065039488342d43ae06d4729d955d4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fb74defa1cca1a73177c0c761e641332e4f979a3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00176
epssPercentile: 0.06304
ingestedAt: '2026-07-11T19:15:12.249Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

bpf, arm64: Fix off-by-one in check_imm signed range check

check_imm(bits, imm) is used in the arm64 BPF JIT to verify that
a branch displacement (in arm64 instruction units) fits into the
signed N-bit immediate field of a B, B.cond or CBZ/CBNZ encoding
before it is handed to the encoder. The macro currently tests for
(imm > 0 && imm >> bits) || (imm < 0 && ~imm >> bits) which admits
values in [-2^N, 2^N) — effectively a signed (N+1)-bit range. A
signed N-bit field only holds [-2^(N-1), 2^(N-1)), so the check
admits one extra bit of range on each side.

In particular, for check_imm19(), values in [2^18, 2^19) slip past
the check but do not fit into the 19-bit signed imm19 field of
B.cond. aarch64_insn_encode_immediate() then masks the raw value
into the 19-bit field, setting bit 18 (the sign bit) and flipping
a forward branch into a backward one. Same class of issue exists
for check_imm26() and the B/BL encoding. Shift by (bits - 1)
instead of bits so the actual signed N-bit range is enforced.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.