CVE-2026-23231: netfilter: nf_tables: fix use-after-free in nf_tables_addchain()

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• linux linux kernel3.16 and later · before 6.1.165
• linux linux kernel6.2 and later · before 6.6.128
• linux linux kernel6.7 and later · before 6.12.75
• linux linux kernel6.13 and later · before 6.18.14
• linux linux kernel6.19 and later · before 6.19.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

• Linux Linux

  • 3.16affected
  • 91c7b38dc9f0de4f7f444b796d14476bc12df7bc and later · before 2a6586ecfa4ce1413daaafee250d2590e05f1a33affected · git
  • 91c7b38dc9f0de4f7f444b796d14476bc12df7bc and later · before 7017745068a9068904e1e7a1b170a5785647cc81affected · git
  • 91c7b38dc9f0de4f7f444b796d14476bc12df7bc and later · before f3fe58ce37926a10115ede527d59b91bcc05400aaffected · git
  • 91c7b38dc9f0de4f7f444b796d14476bc12df7bc and later · before dbd0af8083dd201f07c49110b2ee93710abdff28affected · git
  • 91c7b38dc9f0de4f7f444b796d14476bc12df7bc and later · before 2f9a4ffeb763aec822f8ff3d1e82202d27d46d4baffected · git
  • 91c7b38dc9f0de4f7f444b796d14476bc12df7bc and later · before 71e99ee20fc3f662555118cf1159443250647533affected · git
  • before 3.16not affected · semver
  • 6.1.165 and later · up to and including 6.1.*not affected · semver
  • 6.6.128 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
  90Now
• CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
  89Now
• CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
  85Now

Published before and after this one in the same product

• ← EarlierCVE-2026-23237Mar 4, 2026 · platform/x86: classmate-laptop: Add missing NULL pointer checks
  22Monitor
• ← EarlierCVE-2026-23238Mar 4, 2026 · romfs: check sb_set_blocksize() return value
  22Monitor
• Later →CVE-2025-71238Mar 4, 2026 · scsi: qla2xxx: Fix bsg_done() causing double free
  31Monitor

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1free(dev->buf);2/* ... another thread is still running ... */3process(dev->buf);

1lock(&dev->lock);2free(dev->buf);3dev->buf = NULL;4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.