CVE-2026-93785 json
cifs: validate idmap key payload length
published 2026-09-24 45 d ago modified 2026-10-03 37 d ago also EUVD-2026-86172
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 6%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Linux Linux 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2
- linux Debian 12 6.1.190-1
- linux Debian 13 6.12.111-1
- linux Debian 14 7.2.6-1
- linux-6.12 Debian 12 6.12.111-1~deb12u1
debian advisories DEBIAN-CVE-2026-93785
- linux Ubuntu 22.04 LTS 5.15.0-202.212
- linux Ubuntu 26.04 LTS 7.0.0-42.42
- linux-aws Ubuntu 22.04 LTS 5.15.0-1119.126
- linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
- linux-gcp Ubuntu 22.04 LTS 5.15.0-1120.130
- linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
- linux-gke Ubuntu 22.04 LTS 5.15.0-1115.121
- linux-ibm Ubuntu 22.04 LTS 5.15.0-1113.117
ubuntu advisories UBUNTU-CVE-2026-93785
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel-rt Linux Micro 6.2 6.12.0-160000.40.1
- kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1
- kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1
- kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.40.1
- kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1.160000.2.29
- kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.40.1
- kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.40.1
- kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.40.1
suse advisories SUSE-SU-2026:5121-1SUSE-SU-2026:24422-1SUSE-SU-2026:24446-1SUSE-SU-2026:24437-1SUSE-SU-2026:24386-1
- kernel-rt openSUSE Leap 16.0 6.12.0-160000.40.1
- dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-64kb openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-syms openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-azure openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-source openSUSE Leap 16.0 6.12.0-160000.40.1
- kernel-default openSUSE Leap 16.0 6.12.0-160000.40.1
opensuse advisories openSUSE-SU-2026:22167-1
- kernel Azure Linux 3.0 6.6.158.1-1
azure linux advisories AZL-103994
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/eeac976b74b4f697cfc517187b7cbfd72652dbbc commit
- git.kernel.org/stable/c/125b05ac8ca8758950e4369c1542d57a162f504c commit
- git.kernel.org/stable/c/945f6cde6bcf8f08f6fa5df8882b1b9582e55efa commit
- git.kernel.org/stable/c/3a4a34a732e8a08309eed0a74314dbd9f2f1c972 commit
- git.kernel.org/stable/c/6cfeef221ac00d63c07f6122f58e6159bde69ca0 commit
- git.kernel.org/stable/c/8b12f65d7caf16d124098cb4895a203367d35b57 commit
- git.kernel.org/stable/c/455488cd5054bcc59db40fa1cc2c004031a5b2a5 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-93785 updated cvss 5.5
kernel: cifs: validate idmap key payload length
-
Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9affected: no fix available “Fix deferred”
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 morenot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/eeac976b74b4f697cfc517187b7cbfd72652dbbc
- git.kernel.org /stable/c/125b05ac8ca8758950e4369c1542d57a162f504c
- git.kernel.org /stable/c/945f6cde6bcf8f08f6fa5df8882b1b9582e55efa
- git.kernel.org /stable/c/3a4a34a732e8a08309eed0a74314dbd9f2f1c972
- git.kernel.org /stable/c/6cfeef221ac00d63c07f6122f58e6159bde69ca0
- git.kernel.org /stable/c/8b12f65d7caf16d124098cb4895a203367d35b57
- git.kernel.org /stable/c/455488cd5054bcc59db40fa1cc2c004031a5b2a5
Sources
- CVE List CVE-2026-93785
- NVD CVE-2026-93785
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.