Vulnerability · CVE-2026-99063
dm ioctl: don't let data_start run past the buffer
Published Oct 23, 2026 · catalog updated Oct 29, 2026 · Linux Linux
Last checked Nov 6, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-99063. EPSS is 0.18%. Act only if a listed version of Linux Linux is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-100082 · Unknown
- CVE-2026-100080 · Unknown
- CVE-2026-100081 · Unknown
- CVE-2026-99260 · Medium
- CVE-2026-99259 · Medium
- Severity
- High—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.18%
- Remediation
- Advisory link
- Affected products
- Debian:12 linux · Debian:13 linux · Debian:14 linux · Linux Kernel · Ubuntu:16.04:LTS linux-hwe-edge · Ubuntu:Pro:14.04:LTS linux
In the Linux kernel, the following vulnerability has been resolved: dm ioctl: don't let data_start run past the buffer struct dm_ioctl has seven bytes of trailing padding, so the smallest buffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data), is seven bytes shorter than sizeof(struct dm_ioctl). get_result_buffer() sets data_start to sizeof(struct dm_ioctl) without looking at how big the buffer actually is. Ask for the minimum and data_start ends up seven bytes past the end. Callers add it to data_size, and ctl_ioctl() copies that much back to userspace: BUG: KASAN: slab-out-of-bounds in _copy_to_user+0xad/0xd0 Read of size 312 at addr ffff8880169e4c00 by task repro-dm/140 ctl_ioctl+0x5e3/0xcb0 dm_ctl_ioctl+0x25/0x40 allocated 305-byte region [ffff8880169e4c00, ffff8880169e4d31) A DM_LIST_DEVICES with data_size set to 305 is enough to hit it, and the seven bytes that leak are whatever sat next to the allocation. Clamp data_start to the buffer size. Note that this is not a security bug because the out-of-bounds read can only be triggered by root.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
- Debian:13 linux0 → 6.12.113-1
- Debian:14 linux0 → 7.2.11-1
- Linux Kernel2.6.25 → 6.6.160; 6.7.0 → 6.12.113; 6.13.0 → 6.18.57
- Ubuntu:16.04:LTS linux-hwe-edge4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1
- Ubuntu:Pro:14.04:LTS linux3.11.0-12.19, 3.12.0-1.3, 3.12.0-2.5
- Ubuntu:Pro:14.04:LTS linux-aws4.4.0-1002.2, 4.4.0-1003.3, 4.4.0-1005.5
- Ubuntu:Pro:14.04:LTS linux-azure4.15.0-1023.24~14.04.1, 4.15.0-1030.31~14.04.1, 4.15.0-1031.32~14.04.1
- Ubuntu:Pro:14.04:LTS linux-lts-xenial4.4.0-13.29~14.04.1, 4.4.0-14.30~14.04.2, 4.4.0-15.31~14.04.1
- Ubuntu:Pro:16.04:LTS linux4.2.0-16.19, 4.2.0-17.21, 4.2.0-19.23
- Ubuntu:Pro:16.04:LTS linux-aws4.4.0-1001.10, 4.4.0-1003.12, 4.4.0-1004.13
- Ubuntu:Pro:16.04:LTS linux-aws-hwe4.15.0-1030.31~16.04.1, 4.15.0-1031.33~16.04.1, 4.15.0-1032.34~16.04.1
- Ubuntu:Pro:16.04:LTS linux-azure4.11.0-1009.9, 4.11.0-1011.11, 4.11.0-1013.13
- Ubuntu:Pro:16.04:LTS linux-gcp4.10.0-1004.4, 4.10.0-1006.6, 4.10.0-1007.7
- Ubuntu:Pro:16.04:LTS linux-hwe4.8.0-36.36~16.04.1, 4.8.0-39.42~16.04.1, 4.8.0-41.44~16.04.1
- Ubuntu:Pro:16.04:LTS linux-kvm4.4.0-1004.9, 4.4.0-1007.12, 4.4.0-1008.13
- vendor Linux Linuxversion unspecified
How to fix CVE-2026-99063
Upgrade
CVE-2026-99063 lists a fix boundary at 6.12.113-1. Compare the installed build with that boundary before you change production.
Version check
Fixed in 6.12.113-1 · 11 other ranges on the advisory
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-99063. EPSS is 0.18%. Act only if a listed version of Linux Linux is installed.
Which versions are affected?
Compare what you have installed with Kernel 2.6.25 → 6.6.160; 6.7.0 → 6.12.113; 6.13.0 → 6.18.57. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.18%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 23, 2026 · OpenSSF OSV / OSV Scanner
Detected
Oct 23, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux fixed in 6.12.113-1; linux fixed in 7.2.11-1
Oct 23, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux fixed in 6.12.113-1
Oct 23, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux fixed in 7.2.11-1
Oct 23, 2026 · OpenSSF OSV / OSV Scanner
Updated
The description or metadata changed.
Oct 24, 2026 · OpenSSF OSV / OSV Scanner
Fix available
Kernel fixed in 6.6.160; Kernel fixed in 6.12.113; Kernel fixed in 6.18.57; Kernel fixed in 7.2.11
Oct 24, 2026 · OpenSSF OSV / OSV Scanner
Fix available
Kernel fixed in 6.6.160; 6.7.0
Oct 24, 2026 · OpenSSF OSV / OSV Scanner
Updated
In the Linux kernel, the following vulnerability has been resolved: dm ioctl: don't let data_start run past the buffer struct dm_ioctl has seven bytes of trailing padding, so the smallest buffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data), is seven bytes shorter than sizeof(struct dm_ioctl). get_result_buffer() sets data_start to sizeof(struct dm_ioctl) without looking at how
Oct 29, 2026 · OpenSSF OSV / OSV Scanner
Updated
In the Linux kernel, the following vulnerability has been resolved: dm ioctl: don't let data_start run past the buffer struct dm_ioctl has seven bytes of trailing padding, so the smallest buffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data), is seven bytes shorter than sizeof(struct dm_ioctl). get_result_buffer() sets data_start to sizeof(struct dm_ioctl) without looking at how
Sources
- CVE.orgVulnerability recordCVE-2026-99063
In the Linux kernel, the following vulnerability has been resolved: dm ioctl: don't let data_start run past the buffer struct dm_ioctl has seven bytes of trailing padding, so the smallest buffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data), is seven bytes shor
cve.org - FIRST EPSSExploitation probabilityCVE-2026-99063
30-day exploitation probability 0.18%
first.org - OpenSSF OSV / OSV ScannerPackage advisoryCVE-2026-99063
dm ioctl: don't let data_start run past the buffer
osv.dev - OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-99063osv.dev
- OpenSSF OSV / OSV ScannerPackage advisoryUBUNTU-CVE-2026-99063osv.dev
- Tenable CVE DatabaseVulnerability recordCVE-2026-99063
In the Linux kernel, the following vulnerability has been resolved: dm ioctl: don't let data_start run past the buffer struct dm_ioctl has seven bytes of trailing padding, so the smallest buffer userspace is allowed to ask for, offsetof(struct dm_ioctl, data), is seven bytes shorter than sizeof(struct dm_ioctl). get_result_buffer() sets data_start to sizeof(struct dm_ioctl) without looking at how
tenable.com - Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-99063osv.dev
References
Freshness
Last verified in this catalog Nov 6, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 31, 2026
- OpenSSF OSV / OSV ScannerOct 29, 2026
- CVE.orgOct 25, 2026
- OpenSSF OSV / OSV ScannerOct 24, 2026
- Trivy Vulnerability DBOct 23, 2026
- Tenable CVE DatabaseOct 23, 2026
- OpenSSF OSV / OSV ScannerOct 23, 2026