CVE-2026-99063dm ioctl: don't let data_start run past the buffer
- —Not scoredno CVSS score yet
- 0.18%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
- 28 days later
· 28 days later
Published
- 7 days later
· 7 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.18% · top 93% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < aaa93e41ae308ad9ff9d9ba3296a0d0f4d45bad3
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < f171054f3c4cfc4dc0cb622ec5b15793e5f23029
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < afe80ec31464f4c54cc1bc658753bc14cb14bd6c
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < 98195e822343a656b92e235847ab3e72b1a3f920
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < e5c3f3d8935ecc64c962fb66e6a86dbf79218f61
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < 5680b6fb3054677d4ee65d3baba24b649f1b430e
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < 725b49c689bbb29ef740b0d6b5ea9390baa9a695
- affected 76c072b48e39e9291fbf02d6c912cf27d65e093d – < 9b3fcf519d370df94a56f3b272d9eddffffa5be8
- affected 2.6.25
- unaffected < 2.6.25
- unaffected 5.10.273 – ≤ 5.10.*
- unaffected 5.15.224 – ≤ 5.15.*
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.113 – ≤ 6.12.*
- unaffected 6.18.57 – ≤ 6.18.*
- unaffected 7.2.11 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/aaa93e41ae308ad9ff9d9ba3296a0d0f4d45bad3 (opens in a new tab)
- https://git.kernel.org/stable/c/f171054f3c4cfc4dc0cb622ec5b15793e5f23029 (opens in a new tab)
- https://git.kernel.org/stable/c/afe80ec31464f4c54cc1bc658753bc14cb14bd6c (opens in a new tab)
- https://git.kernel.org/stable/c/98195e822343a656b92e235847ab3e72b1a3f920 (opens in a new tab)
- https://git.kernel.org/stable/c/e5c3f3d8935ecc64c962fb66e6a86dbf79218f61 (opens in a new tab)
- https://git.kernel.org/stable/c/5680b6fb3054677d4ee65d3baba24b649f1b430e (opens in a new tab)
- https://git.kernel.org/stable/c/725b49c689bbb29ef740b0d6b5ea9390baa9a695 (opens in a new tab)
- https://git.kernel.org/stable/c/9b3fcf519d370df94a56f3b272d9eddffffa5be8 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-108729 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-99063)Record last updated .