Vulnerability in Linux kernel (CVE-2026-98844)
Summary
Vulnerability in Linux kernel (CVE-2026-98844). 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:
netfs: clear post-EOF pagecache when extending a file via write
Fix netfs to erase the contents of a hole created after the EOF by an
ordinary write if dirty data has been previously left there by writes
through an mmapped region. Neither the buffered nor the unbuffered/DIO
write path clears that stale pagecache.
Zero the tail of the folio straddling the EOF before an extending
write. That is the only folio that can hold data written past the EOF
through an mmap, as pages wholly beyond the EOF can't be faulted in.
The folio is zeroed rather than dropped so a concurrent extending write
can't lose data.
Both write paths downgrade the i_rwsem to shared, so extending writes
can run concurrently and the i_size read by the caller may be stale by
the time the folio is locked. Re-read i_size under the folio lock and
clamp the zeroed range up to it, so a racing write that already put
data into the folio isn't clobbered.
Wait for any writeback on the folio to finish before zeroing it so that
the pagecache isn't modified while it may still be read by the transport
during transmission. Honour IOCB_NOWAIT by returning -EAGAIN rather
than blocking on the folio lock, on writeback, or in folio_mkclean()'s
rmap walk when the folio is mapped.
truncate_pagecache() can't be used here: it must be called with the
i_rwsem held exclusively, but these write paths only hold it shared,
and it would block unconditionally, brea…
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-2026-98844 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-2026-98844" on the vendor's site.
CVE-2026-98844 (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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-98844 linux Fixed in: 6.12.113-1
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com