Vulnerability in Linux kernel (CVE-2026-90117)
Summary
Vulnerability in Linux kernel (CVE-2026-90117). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
ntfs: validate usa_ofs before preserving the update sequence number
When ntfs_mft_record_alloc() reuses a free mft record it reads the old
update sequence number straight from the on-disk record:
usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs));
Here m points into the raw $MFT page-cache folio, which still holds
unvalidated, MST-protected bytes: the folio is read by a plain
iomap_read_folio() and neither post_read_mst_fixup() nor
ntfs_mft_record_check() has run on it (both work on private copies).
m->usa_ofs is therefore an untrusted u16, and a corrupted record can put
it past the end of the record so the two-byte read lands outside the
folio. Reading such a record while creating a file gives, under KASAN:
BUG: KASAN: use-after-free in ntfs_mft_record_alloc+...
Read of size 2 at addr ...
ntfs_mft_record_alloc -> __ntfs_create -> ntfs_create -> path_openat
Only preserve the old update sequence number when usa_ofs is even and in
range, mirroring the check ntfs_mft_record_check() already applies;
otherwise leave usn zero, which the existing restore below skips.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-90117 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90117" on the vendor's site.
CVE-2026-90117 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com