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CVE-2026-93785

Linux: cifs: validate idmap key payload length

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)0.17%Chance of exploitation activity in the next 30 days, higher than 6% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in125b05ac8ca8758950e4369c1542d57a162f504cAlso 945f6cde6bcf8f08f6fa5df8882b1b9582e55efa, 3a4a34a732e8a08309eed0a74314dbd9f2f1c972 and 3 moreCVE List
Published24 Sep 2026Updated 3 Oct 2026CVE List

What fixes it

  • 125b05ac8ca8758950e4369c1542d57a162f504cLinuxCVE List
  • 945f6cde6bcf8f08f6fa5df8882b1b9582e55efaLinuxCVE List
  • 3a4a34a732e8a08309eed0a74314dbd9f2f1c972LinuxCVE List
  • 6cfeef221ac00d63c07f6122f58e6159bde69ca0LinuxCVE List
  • 8b12f65d7caf16d124098cb4895a203367d35b57LinuxCVE List
  • 455488cd5054bcc59db40fa1cc2c004031a5b2a5LinuxCVE List

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:

cifs: validate idmap key payload length

The cifs.idmap key type stores its payload length in key->datalen, which is limited to U16_MAX. Accepting a larger key payload truncates the recorded length and can make later users interpret the payload using inconsistent bounds.

Reject oversized preparsed payloads before allocating or copying them. This keeps key->datalen consistent with the stored data for both inline and separately allocated idmap payloads.

Text from CVE List

Affected versions 16

  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before eeac976b74b4f697cfc517187b7cbfd72652dbbcCVE List
  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before 125b05ac8ca8758950e4369c1542d57a162f504cCVE List
  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before 945f6cde6bcf8f08f6fa5df8882b1b9582e55efaCVE List
  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before 3a4a34a732e8a08309eed0a74314dbd9f2f1c972CVE List
  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before 6cfeef221ac00d63c07f6122f58e6159bde69ca0CVE List
  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before 8b12f65d7caf16d124098cb4895a203367d35b57CVE List
  • Linuxaffected: 21fed0d5b763b94a7d1568c27d0cce892ab8d43e before 455488cd5054bcc59db40fa1cc2c004031a5b2a5CVE List
  • Linuxaffected: 3.2CVE List
  • Linuxunaffected: all versions before 3.2CVE 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: 7.2CVE List

References 7