VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98484: Linux kernel · netfilter: nf_tables: skip expired catchall elements on insert and delete

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 70194dc37670bd08e44b471389861cc01bd3a3c9 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:07 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 70194dc37670bd08e44b471389861cc01bd3a3c9, 12cf803edfffef96f6415f0b5dbc7ec88842ea0f, 5e20b39aa7844769a7a782484bc1a809ffbc513e +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ aaa31047a6d25da0fa101da1ed544e1247949b40, < 70194dc37670bd08e44b471389861cc01bd3a3c9	Fixed in 70194dc37670bd08e44b471389861cc01bd3a3c9
LinuxLinux	Affected ≥ aaa31047a6d25da0fa101da1ed544e1247949b40, < 12cf803edfffef96f6415f0b5dbc7ec88842ea0f	Fixed in 12cf803edfffef96f6415f0b5dbc7ec88842ea0f
LinuxLinux	Affected ≥ aaa31047a6d25da0fa101da1ed544e1247949b40, < 5e20b39aa7844769a7a782484bc1a809ffbc513e	Fixed in 5e20b39aa7844769a7a782484bc1a809ffbc513e
LinuxLinux	Affected ≥ aaa31047a6d25da0fa101da1ed544e1247949b40, < 4fb8b1ccc475651e480e509de126bb9ce7f3cff9	Fixed in 4fb8b1ccc475651e480e509de126bb9ce7f3cff9
LinuxLinux	Affected ≥ aaa31047a6d25da0fa101da1ed544e1247949b40, < 2f07da3881525f7cbfed1ced2796c71a201505b9	Fixed in 2f07da3881525f7cbfed1ced2796c71a201505b9
LinuxLinux	Affected =5.13	Fixed in–

Description

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.

References

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