Skip to main content
VulnerabilityPublished Updated

CVE-2026-31507: Linux kernel · net/smc: fix double-free of smc_spd_priv when tee() duplicates splice pipe buffer

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in ae5575e660410c8d2c5d38fb28a0f37aea945676 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:00 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in ae5575e660410c8d2c5d38fb28a0f37aea945676, 98ba5cb274768146e25ffbfde47753652c1c20d3, 81acbd345d405994875d419d43b319fee0b9ad62 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 22 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f, < ae5575e660410c8d2c5d38fb28a0f37aea945676
Fixed in
  • ae5575e660410c8d2c5d38fb28a0f37aea945676
LinuxLinuxAffected
  • ≥ 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f, < 98ba5cb274768146e25ffbfde47753652c1c20d3
Fixed in
  • 98ba5cb274768146e25ffbfde47753652c1c20d3
LinuxLinuxAffected
  • ≥ 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f, < 81acbd345d405994875d419d43b319fee0b9ad62
Fixed in
  • 81acbd345d405994875d419d43b319fee0b9ad62
LinuxLinuxAffected
  • ≥ 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f, < 54c87a730157868543ebdfa0ecb21b4590ed23a5
Fixed in
  • 54c87a730157868543ebdfa0ecb21b4590ed23a5
LinuxLinuxAffected
  • ≥ 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f, < 24dd586bb4cbba1889a50abe74143817a095c1c9
Fixed in
  • 24dd586bb4cbba1889a50abe74143817a095c1c9
LinuxLinuxAffected
  • ≥ 9014db202cb764b8e14c53e7bacc81f9a1a2ba7f, < 7e8916f46c2f48607f907fd401590093753a6bc5
Fixed in
  • 7e8916f46c2f48607f907fd401590093753a6bc5

AI-suggested

A fix is available and has been applied in multiple Linux kernel commits. Users should update to a fixed kernel version containing these commits. The vendor advisory indicates that tee() and splice_pipe_to_pipe() calls that attempt to duplicate SMC splice buffers now return -EFAULT, preventing exploitation. Users needing to duplicate SMC socket data should switch to a copy-based read path as the duplication method is no longer supported. No additional mitigation is required beyond applying the official fix.

Description

CVE-2026-31507 is a high-severity use-after-free vulnerability in the Linux kernel's net/smc subsystem. It occurs due to a double-free of the smc_spd_priv structure when the tee() system call duplicates a splice pipe buffer. This leads to a kernel NULL pointer dereference and potential kernel panic. The flaw arises because the smc_spd_priv pointer is shared between the original and cloned pipe buffers without proper reference counting, causing smc_rx_pipe_buf_release() to free the same object twice. The vulnerability affects Linux kernel version 4.18 and has been fixed in multiple subsequent commits.

References

Community reviews

Loading reviews…