High 7.8Published Nov 12, 2025

CVE-2025-40198ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()

Updated under an hour ago (Oct 27, 2026, 6:50 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Unlike other strings in the ext4 superblock, we rely on tune2fs to make sure s_mount_opts is NUL terminated. Harden parse_apply_sb_mount_options() by treating s_mount_opts as a potential __nonstring.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Deferred
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	8b67f04ab9de5d8f3a71aef72bf02c995a506db5 builds before 7bf46ff83a0ef11836e38ebd72cdc5107209342d; from 8b67f04ab9de5d8f3a71aef72bf02c995a506db5 before b2bac84fde28fb6a88817b8b761abda17a1d300b; from 8b67f04ab9de5d8f3a71aef72bf02c995a506db5 before e651294218d2684302ee5ed95ccf381646f3e5b4; from 8b67f04ab9de5d8f3a71aef72bf02c995a506db5 before 01829af7656b56d83682b3491265d583d502e502; 8b67f04ab9de5d8f3a71aef72bf02c995a506db5 builds before 2a0cf438320cdb783e0378570744c0ef0d83e934; from 8b67f04ab9de5d8f3a71aef72bf02c995a506db5 before a6e94557cd05adc82fae0400f6e17745563e5412; from 8b67f04ab9de5d8f3a71aef72bf02c995a506db5 before 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8	CNA record

References

References

https://git.kernel.org/stable/c/7bf46ff83a0ef11836e38ebd72cdc5107209342d
https://git.kernel.org/stable/c/b2bac84fde28fb6a88817b8b761abda17a1d300b
https://git.kernel.org/stable/c/e651294218d2684302ee5ed95ccf381646f3e5b4
https://git.kernel.org/stable/c/01829af7656b56d83682b3491265d583d502e502
https://git.kernel.org/stable/c/2a0cf438320cdb783e0378570744c0ef0d83e934
https://git.kernel.org/stable/c/a6e94557cd05adc82fae0400f6e17745563e5412
https://git.kernel.org/stable/c/8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.