CVE-2026-31474: can: isotp: fix tx.buf use-after-free in isotp_sendmsg()

Affected versions

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

• linux linux kernel6.4.1 and later · before 6.6.131
• linux linux kernel6.7 and later · before 6.12.80
• linux linux kernel6.13 and later · before 6.18.21
• linux linux kernel6.19 and later · before 6.19.11
• linux linux kernel6.4
• linux linux kernel7.0

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

  • 6.4affected
  • 96d1c81e6a0478535342dff6c730adb076cd84e8 and later · before cb3d6efa78460e6d50bf68806d0db66265709f64affected · git
  • 96d1c81e6a0478535342dff6c730adb076cd84e8 and later · before 9649d051e54413049c009638ec1dc23962c884a4affected · git
  • 96d1c81e6a0478535342dff6c730adb076cd84e8 and later · before eec8a1b18a79600bd4419079dc0026c1db72a830affected · git
  • 96d1c81e6a0478535342dff6c730adb076cd84e8 and later · before 2e62e7051eca75a7f2e3d52d62ec10d7d7aa358caffected · git
  • 96d1c81e6a0478535342dff6c730adb076cd84e8 and later · before 424e95d62110cdbc8fd12b40918f37e408e35a92affected · git
  • before 6.4not affected · semver
  • 6.6.131 and later · up to and including 6.6.*not affected · semver
  • 6.12.80 and later · up to and including 6.12.*not affected · semver
  • 6.18.21 and later · up to and including 6.18.*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-2026-31470Apr 22, 2026 · virt: tdx-guest: Fix handling of host controlled 'quote' buffer length
  28Monitor
• ← EarlierCVE-2026-31473Apr 22, 2026 · media: mc, v4l2: serialize REINIT and REQBUFS with req_queue_mutex
  31Monitor
• Later →CVE-2026-31478Apr 22, 2026 · ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()
  39Monitor

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.