---
id: CVE-2026-43453
title: 'netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()

  pipapo_drop() passes rulemap[i + 1].n to pipapo_unmap() as the
  to_offset argument on every ite…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    1957e793196e7f8557374fd4eda53abcbb42e1c0
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    57fb87ca095d5127cd7a27583b8ec43dcf7c9e9e
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    60c1d18781e37bfb96290b86510eb01c5fa24d75
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    0a55d62cdb628923d8a21724374a70c76ac7d19d
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    dfbdac719198778b581bc0dd055df2542edb8c62
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    e047f6fbb975f685d6c9fcef95b3b7787a79b46d
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    324b749aa5b2d516ccfab933df9d3f56e7807f5f
  - >-
    Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da <
    d6d8cd2db236a9dd13dbc2d05843b3445cc964b5
  - Linux 5.6
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T15:39:22.846644Z'
published: '2026-05-08'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T15:42:55.723Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43453'
references:
  - url: 'https://git.kernel.org/stable/c/1957e793196e7f8557374fd4eda53abcbb42e1c0'
  - url: 'https://git.kernel.org/stable/c/57fb87ca095d5127cd7a27583b8ec43dcf7c9e9e'
  - url: 'https://git.kernel.org/stable/c/60c1d18781e37bfb96290b86510eb01c5fa24d75'
  - url: 'https://git.kernel.org/stable/c/0a55d62cdb628923d8a21724374a70c76ac7d19d'
  - url: 'https://git.kernel.org/stable/c/dfbdac719198778b581bc0dd055df2542edb8c62'
  - url: 'https://git.kernel.org/stable/c/e047f6fbb975f685d6c9fcef95b3b7787a79b46d'
  - url: 'https://git.kernel.org/stable/c/324b749aa5b2d516ccfab933df9d3f56e7807f5f'
  - url: 'https://git.kernel.org/stable/c/d6d8cd2db236a9dd13dbc2d05843b3445cc964b5'
tags:
  - cve.org
epss: 0.00126
epssPercentile: 0.02283
ingestedAt: '2026-11-06T15:54:03.905Z'
---

## Overview

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

netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()

pipapo_drop() passes rulemap[i + 1].n to pipapo_unmap() as the
to_offset argument on every iteration, including the last one where
i == m->field_count - 1. This reads one element past the end of the
stack-allocated rulemap array (declared as rulemap[NFT_PIPAPO_MAX_FIELDS]
with NFT_PIPAPO_MAX_FIELDS == 16).

Although pipapo_unmap() returns early when is_last is true without
using the to_offset value, the argument is evaluated at the call site
before the function body executes, making this a genuine out-of-bounds
stack read confirmed by KASAN:

  BUG: KASAN: stack-out-of-bounds in pipapo_drop+0x50c/0x57c [nf_tables]
  Read of size 4 at addr ffff8000810e71a4

  This frame has 1 object:
   [32, 160) 'rulemap'

  The buggy address is at offset 164 -- exactly 4 bytes past the end
  of the rulemap array.

Pass 0 instead of rulemap[i + 1].n on the last iteration to avoid
the out-of-bounds read.

## Affected

- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < 1957e793196e7f8557374fd4eda53abcbb42e1c0`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < 57fb87ca095d5127cd7a27583b8ec43dcf7c9e9e`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < 60c1d18781e37bfb96290b86510eb01c5fa24d75`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < 0a55d62cdb628923d8a21724374a70c76ac7d19d`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < dfbdac719198778b581bc0dd055df2542edb8c62`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < e047f6fbb975f685d6c9fcef95b3b7787a79b46d`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < 324b749aa5b2d516ccfab933df9d3f56e7807f5f`
- `Linux >= 3c4287f62044a90e73a561aa05fc46e62da173da < d6d8cd2db236a9dd13dbc2d05843b3445cc964b5`
- `Linux 5.6`

## Remediation

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