All vulnerabilities
CVE-2026-97568

Linux: mptcp: syncookies: remember the request backup flag

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.21%Chance of exploitation activity in the next 30 days, higher than 10% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1668b34452009d27be3262646de748a3e48ffd51Also 360d99258a6402cb8e49771460944f19f04d25b7, 61178d0b85b4b1b53e78b06e89d018d22d102f88 and 7 moreCVE List
Published25 Sep 2026Updated 19 Oct 2026CVE List

What fixes it

  • 1668b34452009d27be3262646de748a3e48ffd51LinuxCVE List
  • 360d99258a6402cb8e49771460944f19f04d25b7LinuxCVE List
  • 61178d0b85b4b1b53e78b06e89d018d22d102f88LinuxCVE List
  • 00b2bd518911e0daab00f4749cce68c191ccebb4LinuxCVE List
  • 06d649f9cd03a9f8e768a658b20acf8d2c8022e0LinuxCVE List
  • 5.10.271LinuxCVE List
Show all 10 fixed versions

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

In the Linux kernel, the following vulnerability has been resolved:

mptcp: syncookies: remember the request backup flag

Instead of using an uninitialised bit when copying the info in subflow_ulp_clone().

To fix this, no need to extend the join_entry structure: backup is coming from struct mptcp_subflow_request_sock, only one bit. Do the same here by using one bit for both.

Text from CVE List

Affected versions 24

  • Linuxaffected: 1008f2bcbc8e461c1df3aebba30ac4f616ebe570 before c97fa2c7ada82d4cac1c6c00643238dc4c462f15CVE List
  • Linuxaffected: 6f01f41b6a492ddf2da7609967cfaf57e7ca48a7 before 1668b34452009d27be3262646de748a3e48ffd51CVE List
  • Linuxaffected: 09176f80995105c62939728fbad5c437d61e7ff4 before b138e7dc719f0a3949de8bb6500b8cf1604eea06CVE List
  • Linuxaffected: 8ed3e34c766e8264d5d2e0436f86c51604d6a8a7 before 360d99258a6402cb8e49771460944f19f04d25b7CVE List
  • Linuxaffected: efd340bf3d7779a3a8ec954d8ec0fb8a10f24982 before 61178d0b85b4b1b53e78b06e89d018d22d102f88CVE List
  • Linuxaffected: efd340bf3d7779a3a8ec954d8ec0fb8a10f24982 before 00b2bd518911e0daab00f4749cce68c191ccebb4CVE List
  • Linuxaffected: efd340bf3d7779a3a8ec954d8ec0fb8a10f24982 before 06d649f9cd03a9f8e768a658b20acf8d2c8022e0CVE List
  • Linuxaffected: efd340bf3d7779a3a8ec954d8ec0fb8a10f24982 before b76c0e28b392620dfbaf92cdeedbf115820b44cbCVE List
  • Linuxaffected: 73e2baa301ee3f62ff971e68877adeb37f98cc67CVE List
  • Linuxaffected: 5.10.224 before 5.10.271CVE List
  • Linuxaffected: 5.15.165 before 5.15.222CVE List
  • Linuxaffected: 6.1.104 before 6.1.189CVE List
  • Linuxaffected: 6.6.45 before 6.6.158CVE List
  • Linuxaffected: 6.10.4 before 6.11CVE List
  • Linuxaffected: 6.11CVE List
  • Linuxunaffected: all versions before 6.11CVE List
  • Linuxunaffected: 5.10.271 through 5.10.*CVE List
  • Linuxunaffected: 5.15.222 through 5.15.*CVE List
  • Linuxunaffected: 6.1.189 through 6.1.*CVE List
  • Linuxunaffected: 6.6.158 through 6.6.*CVE List
  • Linuxunaffected: 6.12.111 through 6.12.*CVE List
  • Linuxunaffected: 6.18.53 through 6.18.*CVE List
  • Linuxunaffected: 7.2.7 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 8