CVE-2025-40198: Linux kernel · ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Unlike
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
AI-suggested
Since the vulnerability is resolved in the Linux kernel, applying the official kernel updates when available is recommended. No vendor advisory or patch links are provided in the input data, so monitoring official Linux kernel security advisories is advised.
Description
A high-severity vulnerability in the Linux kernel's ext4 filesystem code involving a potential buffer over-read in the parse_apply_sb_mount_options() function has been resolved. The issue arises because the s_mount_opts string in the ext4 superblock was assumed to be NUL terminated by tune2fs, but this assumption was hardened to treat s_mount_opts as a potential non-string to avoid over-read. This vulnerability could impact confidentiality, integrity, and availability of the system. No known exploits are reported in the wild. No specific affected versions are provided. Patch status is not confirmed in the provided data.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40198 (opens in a new tab)
- git.kernel.org/stable/c/01829af7656b56d83682b3491265d583d502e502 (opens in a new tab)
- git.kernel.org/stable/c/2a0cf438320cdb783e0378570744c0ef0d83e934 (opens in a new tab)
- git.kernel.org/stable/c/7bf46ff83a0ef11836e38ebd72cdc5107209342d (opens in a new tab)
- git.kernel.org/stable/c/8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 (opens in a new tab)
- git.kernel.org/stable/c/a6e94557cd05adc82fae0400f6e17745563e5412 (opens in a new tab)
- git.kernel.org/stable/c/b2bac84fde28fb6a88817b8b761abda17a1d300b (opens in a new tab)
- git.kernel.org/stable/c/e651294218d2684302ee5ed95ccf381646f3e5b4 (opens in a new tab)