---
id: CVE-2026-98484
title: 'netfilter: nf_tables: skip expired catchall elements on insert and delete'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nf_tables: skip expired catchall elements on insert and delete

  nft_setelem_catchall_insert() looks up duplicates with
  nft_set_elem_active() only, while nft_…
severity: low
cvss: 3.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L'
cvssSource: vendor
cwe:
  - CWE-1025
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 <
    5e20b39aa7844769a7a782484bc1a809ffbc513e
  - >-
    Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 <
    2f07da3881525f7cbfed1ced2796c71a201505b9
  - >-
    Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 <
    12cf803edfffef96f6415f0b5dbc7ec88842ea0f
  - >-
    Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 <
    4fb8b1ccc475651e480e509de126bb9ce7f3cff9
  - >-
    Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 <
    70194dc37670bd08e44b471389861cc01bd3a3c9
  - Linux 5.13
published: '2026-10-18'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:55:11.288Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98484'
references:
  - url: 'https://git.kernel.org/stable/c/5e20b39aa7844769a7a782484bc1a809ffbc513e'
  - url: 'https://git.kernel.org/stable/c/2f07da3881525f7cbfed1ced2796c71a201505b9'
  - url: 'https://git.kernel.org/stable/c/12cf803edfffef96f6415f0b5dbc7ec88842ea0f'
  - url: 'https://git.kernel.org/stable/c/4fb8b1ccc475651e480e509de126bb9ce7f3cff9'
  - url: 'https://git.kernel.org/stable/c/70194dc37670bd08e44b471389861cc01bd3a3c9'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98484.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98484'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2554907'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98484'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98484'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98484.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.002
epssPercentile: 0.09774
ingestedAt: '2026-10-18T15:45:12.293Z'
---

## Overview

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

netfilter: nf_tables: skip expired catchall elements on insert and delete

nft_setelem_catchall_insert() looks up duplicates with
nft_set_elem_active() only, while nft_set_catchall_lookup() and the
dump path additionally skip expired elements.

Once a catchall element with a timeout expires, this predicate drift
makes it invisible to userspace dumps, yet it still blocks
re-insertion: with NLM_F_EXCL the request fails with -EEXIST, and
without it the request reports success but silently inserts nothing.
The stale entry only goes away when the (user-tunable) gc interval
elapses, so the catchall rule may silently stop matching for an
arbitrarily long time after its first expiration.

The delete path shows the same drift: nft_setelem_catchall_deactivate()
picks the first active-next entry in the catchall list, so with an
expired entry still pending GC it retires the stale entry instead of
the fresh one, and it deactivates an element that userspace no longer
sees instead of failing with -ENOENT.

Align both walks with the lookup and dump predicates: only an element
that is active and not expired counts as a duplicate or delete
candidate, using the per-netns timestamp taken at transaction start,
in line with the set backend .insert/.deactivate and catchall GC sync
paths.

## Affected

- `Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 < 5e20b39aa7844769a7a782484bc1a809ffbc513e`
- `Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 < 2f07da3881525f7cbfed1ced2796c71a201505b9`
- `Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 < 12cf803edfffef96f6415f0b5dbc7ec88842ea0f`
- `Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 < 4fb8b1ccc475651e480e509de126bb9ce7f3cff9`
- `Linux >= aaa31047a6d25da0fa101da1ed544e1247949b40 < 70194dc37670bd08e44b471389861cc01bd3a3c9`
- `Linux 5.13`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98484.json)