CVE-2026-53615
A local attacker who causes a crafted DOS extended-partition disk image or removable medium to be probed can wrap `cur_start + start` to sector zero and cause libblkid to report a false partition overlapping the MBR.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
util-linux is a random collection of Linux utilities. Before util-linux 2.41.4, `parse_dos_extended()` in `libblkid/src/partitions/dos.c` computes an extended-partition start sector with 32-bit addition and does not apply the extended-area bounds checks to the first two EBR entries. A local attacker who causes a crafted DOS extended-partition disk image or removable medium to be probed can wrap `cur_start + start` to sector zero and cause libblkid to report a false partition overlapping the MBR. This directly compromises the integrity of the reported partition metadata; disk modification or availability loss requires a separate downstream consumer to act on that metadata. This issue is fixed in 2.41.4.
- CVSS 3.1
- 8.0 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H
- EPSS
- 0.18% probability · 7th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Source
- security-advisories@github.com
EPSS moved from 0.2% on 15 October 2026 to 0.2% on 27 October 2026.
References
- https://github.com/util-linux/util-linux/commit/05c2dbadf34cc74192287f377904afaaf4061623
- https://github.com/util-linux/util-linux/commit/a2d858176b609ab5b8535021a3af9cd302d23d31
- https://github.com/util-linux/util-linux/commit/e9d544d013267ea86b70ee8ff78abd280e6641af
- https://github.com/util-linux/util-linux/releases/tag/v2.41.4
- https://github.com/util-linux/util-linux/security/advisories/GHSA-h4rw-gv36-wmp5
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.