CVE-2026-23231

Advisory lineage Upstream: 0 Downstream: 35
Modified
Published: 04 Mar 2026, 12:58
Last modified:02 Jun 2026, 13:01

Vulnerability Summary

Overall Risk (default)
medium
41/100
CVSS Score
7.8 HIGH
v3.1 (nvd)
EPSS Score
0.77% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

04 Mar 2026, 12:58
Published
Vulnerability first disclosed
02 Jun 2026, 13:01
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with no RCU grace period in between. This creates two use-after-free conditions: 1) Control-plane: nf_tables_dump_chains() traverses table->chains under rcu_read_lock(). A concurrent dump can still be walking the chain when the error path frees it. 2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nft_do_chain() via the transient IPv4 hook can still be dereferencing chain->blob_gen_X when the error path frees the chain. Add synchronize_rcu() between nft_chain_del() and the chain destroy so that all RCU readers -- both dump threads and in-flight packet evaluation -- have finished before the chain is freed.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.77%• Percentile: 74%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • linux•linux

    ≥ 91c7b38dc9f0de4f7f444b796d14476bc12df7bc, < 2a6586ecfa4ce1413daaafee250d2590e05f1a33 | ≥ 91c7b38dc9f0de4f7f444b796d14476bc12df7bc, < 7017745068a9068904e1e7a1b170a5785647cc81 | ≥ 91c7b38dc9f0de4f7f444b796d14476bc12df7bc, < f3fe58ce37926a10115ede527d59b91bcc05400a | ≥ 91c7b38dc9f0de4f7f444b796d14476bc12df7bc, < dbd0af8083dd201f07c49110b2ee93710abdff28 | ≥ 91c7b38dc9f0de4f7f444b796d14476bc12df7bc, < 2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b | ≥ 91c7b38dc9f0de4f7f444b796d14476bc12df7bc, < 71e99ee20fc3f662555118cf1159443250647533 | 3.16

  • linux•linux_kernel

    ≥ 3.16, < 6.1.165 | ≥ 6.2, < 6.6.128 | ≥ 6.7, < 6.12.75 | ≥ 6.13, < 6.18.14 | ≥ 6.19, < 6.19.4

References (7)