Vulnerability in Linux kernel (CVE-2026-93255)
Summary
Vulnerability in Linux kernel (CVE-2026-93255). 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:
btrfs: make sure EXTENT_BUFFER_READING is cleared under refs_lock
[FALSE ALERTS]
There is a bug report that the warning inside
invalidate_and_check_btree_folios() got triggered during btrfs/298:
BTRFS info (device sdd): first mount of filesystem f9bf732a-a19b-44b9-99a7-614ddff168e2
BTRFS info (device sdd): using crc32c checksum algorithm
BTRFS error (device sdd): failed to find fsid cb2fdb42-b638-4f2f-badd-4127467ba674 when attempting to open seed devices
BTRFS error (device sdd): failed to read chunk tree: -2
------------[ cut here ]------------
WARNING: disk-io.c:3342 at invalidate_and_check_btree_folios+0x260/0x3c0 [btrfs], CPU#4: mount/125993
CPU: 4 UID: 0 PID: 125993 Comm: mount Tainted: G W OE 7.1.0-rc7-custom+ #1 PREEMPT(full)
Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20250812-19.fc42 08/12/2025
Call trace:
invalidate_and_check_btree_folios+0x260/0x3c0 [btrfs] (P)
open_ctree+0x1f50/0x23b0 [btrfs]
btrfs_get_tree+0x89c/0xc48 [btrfs]
vfs_get_tree+0x30/0x110
vfs_cmd_create+0x58/0xe8
__arm64_sys_fsconfig+0x39c/0x518
invoke_syscall.constprop.0+0x48/0x120
el0_svc_common.constprop.0+0x40/0xe8
do_el0_svc+0x24/0x38
el0_svc+0x50/0x310
el0t_64_sync_handler+0xa0/0xe8
el0t_64_sync+0x198/0x1a0
---[ end trace 0000000000000000 ]---
BTRFS warning (device sdd): unable to release extent buffer 365985792 owner 3 gen 17 refs 3 flags 0x5
[CAUSE]
In that invalidate…
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-2026-93255 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-2026-93255" on the vendor's site.
CVE-2026-93255 (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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-93255 linux Fixed in: 7.2.6-1
- Ubuntu UBUNTU-CVE-2026-93255 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com
- web git.kernel.org