Vulnerability in Linux kernel (CVE-2026-90260)
Summary
Vulnerability in Linux kernel (CVE-2026-90260). Data can be tampered with by attackers.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: don't clobber the extent buffer when zeroing it out
On a zoned filesystem a freed-but-still-dirty tree block is written out
as zeros (EXTENT_BUFFER_ZONED_ZEROOUT) only to keep the zone write
pointer advancing. btree_csum_one_bio() implemented this by memzeroing
the extent buffer's own folios before submission.
That destroys the in-memory buffer while it may still be referenced. In
particular btrfs_free_tree_block() can run on it afterwards and reads
the header to add a delayed reference; once the header has been zeroed
it frees bytenr 0 and corrupts the extent tree (the
btrfs_header_bytenr(buf) != 0 ASSERT in btrfs_free_tree_block(), or an
"unable to find ref" abort). It is flaky and reproduces under fsstress,
e.g. generic/461 and generic/013.
Write the zeros to disk from the shared zero page instead and leave the
extent buffer content untouched, so any later reference - including the
delayed reference from btrfs_free_tree_block() - still sees a valid
header. end_bbio_meta_write() now clears writeback on the buffer's own
folios, as the bio no longer carries them.
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-2026-90260 has been found in Linux kernel.
Data can be tampered with by attackers. CVSS score: 7.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90260" on the vendor's site.
CVE-2026-90260 (Linux kernel) — CVSS v3 7.1
Attack vector: local / no user interaction
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: High (CVSS 7.1/10). Data can be tampered with by attackers.
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 git.kernel.org
- web nvd.nist.gov
- web github.com