Vulnerability in Linux kernel (CVE-2026-89587)
Summary
Vulnerability in Linux kernel (CVE-2026-89587). 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:
ACPI: pfr_update: fix stack buffer overflow in query_capability()
query_capability() copies four ACPI buffer objects returned by the
firmware _DSM into fixed-size u8[16] fields in struct
pfru_update_cap_info using memcpy with the firmware-supplied length:
memcpy(&cap_hdr->code_type,
elements[CAP_CODE_TYPE_IDX].buffer.pointer,
elements[CAP_CODE_TYPE_IDX].buffer.length);
The same pattern repeats for drv_type, platform_id, and oem_id.
If the firmware returns buffer.length > 16 for any of these fields,
memcpy writes past the destination array.
struct pfru_update_cap_info is stack-allocated in pfru_ioctl().
Confirmed with KASAN on 7.2-rc6: three stack-out-of-bounds reports
are generated when a DSM returns 64-byte buffers, with writes reaching
44 bytes past the end of cap_hdr's [64, 156) frame window into
adjacent stack redzones.
Introduce a helper pointer to out_obj->package.elements and use it
to validate each buffer length against its destination field size
before copying, returning -EINVAL if the firmware supplies an
oversized buffer.
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-2026-89587 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-2026-89587" on the vendor's site.
CVE-2026-89587 (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。
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com