CVE-2026-23278: netfilter: nf_tables: always walk all pending catchall elements

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-20 · updated 2026-10-30
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: always walk all pending catchall elements During transaction processing we might have more than one catchall element: 1 live catchall element and 1 pending element that is coming as part of the new batch. If the map holding the catchall elements is also going away, its required to toggle all catchall elements and not just the first viable candidate. Otherwise, we get: WARNING: ./include/net/netfilter/nf_tables.h:1281 at nft_data_release+0xb7/0xe0 [nf_tables], CPU#2: nft/1404 RIP: 0010:nft_data_release+0xb7/0xe0 [nf_tables] [..] __nft_set_elem_destroy+0x106/0x380 [nf_tables] nf_tables_abort_release+0x348/0x8d0 [nf_tables] nf_tables_abort+0xcf2/0x3ac0 [nf_tables] nfnetlink_rcv_batch+0x9c9/0x20e0 [..]

Affected products

Linux kernel: from 4.19.316 before 4.20; from 5.4.262 before 5.5; from 5.10.188 before 5.11; from 5.15.121 before 5.16; from 6.1.36 before 6.2; from 6.3.10 before 6.4 — fixed in 4.20, 5.5, 5.11, 5.16, 6.2, 6.4
Linux: from 5.15.121 before 5.15.224; from 6.1.36 before 6.1.177; from 4.19.316 before 4.20; from 5.4.262 before 5.5; from 5.10.188 before 5.11; from 6.3.10 before 6.4 — fixed in 5.15.224, 6.1.177, 4.20, 5.5, 5.11, 6.4

How to fix

Upgrade to a fixed version: Linux kernel 4.20, 5.5, 5.11, 5.16; Linux 5.15.224, 6.1.177, 4.20, 5.5. Check the vendor advisory for mitigations.

References

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