ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-23231

kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain()

Published Mar 4, 2026 · catalog updated Oct 15, 2026 · Red Hat linux kernel

Check if you run it

No confirmed exploitation is on record for CVE-2026-23231. EPSS is 0.82%. Act only if a listed version of Red Hat linux kernel is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.82%
Remediation
Advisory link
Affected products
cpe linux/linux kernel

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernelversion unspecified

How to fix CVE-2026-23231

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-23231. EPSS is 0.82%. Act only if a listed version of Red Hat linux kernel is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-416: Use After Free. EPSS 0.82%. There is no CISA KEV listing. A public exploit reference is linked in Sources. That is not the same as confirmed exploitation. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 4, 2026 · NIST NVD

    Detected

    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

  2. Oct 15, 2026 · NIST NVD

    Updated

    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

Sources

  • CSAF AdvisoriesVendor advisoryRHSA-2026:9835:CVE-2026-23231

    A flaw was found in the Linux kernel. A local attacker with CAP_NET_ADMIN capabilities, or remote packet traffic, could exploit a use-after-free vulnerability in the nf_tables_addchain() function's error handling. Successful exploitation could lead to a kernel crash, resulting in

    security.access.redhat.com
  • CSAF AdvisoriesVendor advisoryRHSA-2026:9836:CVE-2026-23231

    A flaw was found in the Linux kernel. A local attacker with CAP_NET_ADMIN capabilities, or remote packet traffic, could exploit a use-after-free vulnerability in the nf_tables_addchain() function's error handling. Successful exploitation could lead to a kernel crash, resulting in

    security.access.redhat.com
  • CSAF AdvisoriesVendor advisoryRHSA-2026:9870:CVE-2026-23231

    A flaw was found in the Linux kernel. A local attacker with CAP_NET_ADMIN capabilities, or remote packet traffic, could exploit a use-after-free vulnerability in the nf_tables_addchain() function's error handling. Successful exploitation could lead to a kernel crash, resulting in

    security.access.redhat.com
  • CVE.orgVulnerability recordCVE-2026-23231

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-23231

    30-day exploitation probability 0.8%

    first.org
  • Exploit DatabasePublic exploit reference52549

    Public archive entry. The exploit body is not stored here.

    exploit-db.com
  • NIST NVDVulnerability recordCVE-2026-23231

    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_reg

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.