Vulnerability in Linux kernel (CVE-2026-90047)
Summary
Vulnerability in Linux kernel (CVE-2026-90047). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Don't hand out the flat CCS storage as usable VRAM
get_flat_ccs_offset() reads the base of the flat CCS storage from the
hardware, scales it by the number of enabled L3 nodes, and rounds the
result up to 128K. Everything below that offset is then handed to the
VRAM allocator as usable memory.
Rounding a limit that means "usable memory ends here" upwards publishes
whatever lies between the real base and the rounded one as free memory,
and that memory belongs to the compression hardware. The scaled value
has no reason to be 128K aligned, and on a Battlemage G21 with 16 GiB it
is not:
flat CCS base: raw 0x3fafff800, rounded 0x3fb000000
so the last 2 KiB of page 0x3fafff000 is CCS storage, in the allocator's
pool. Whatever is allocated there gets that tail overwritten by the
compression hardware, which needs no page-table entry, no buffer object
and no GPU submission to do it, and does it before userspace exists.
On this machine a Mesa VM's level-3 page table landed on that page on
every cold boot. It lost the entry covering the compositor's
batch-buffer heap, so the compositor's first submission faulted fetching
its batch and gdm restarted it forever: a black screen on an otherwise
working machine. Restarting gdm cleared it because the next VM's page
tables were allocated somewhere else.
Round down instead, to the page size the allocator works in. On this
machine that excludes exactly one p…
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-2026-90047 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90047" on the vendor's site.
CVE-2026-90047 (Linux kernel) — CVSS v3 7.8
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 7.8/10). Successful exploitation can lead to full system takeover.
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-2026-90047 linux Fixed in: 7.2.6-1
- Ubuntu UBUNTU-CVE-2026-90047 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com