Out-of-Bounds Write in Linux kernel (CVE-2025-39809)
Summary
Out-of-bounds write in Linux kernel (CVE-2025-39809). 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:
HID: intel-thc-hid: intel-quicki2c: Fix ACPI dsd ICRS/ISUB length
The QuickI2C ACPI _DSD methods return ICRS and ISUB data with a
trailing byte, making the actual length is one more byte than the
structs defined.
It caused stack-out-of-bounds and kernel crash:
kernel: BUG: KASAN: stack-out-of-bounds in quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel: Write of size 12 at addr ffff888106d1f900 by task kworker/u33:2/75
kernel:
kernel: CPU: 3 UID: 0 PID: 75 Comm: kworker/u33:2 Not tainted 6.16.0+ #3 PREEMPT(voluntary)
kernel: Workqueue: async async_run_entry_fn
kernel: Call Trace:
kernel:
kernel: dump_stack_lvl+0x76/0xa0
kernel: print_report+0xd1/0x660
kernel: ? __pfx__raw_spin_lock_irqsave+0x10/0x10
kernel: ? __kasan_slab_free+0x5d/0x80
kernel: ? kasan_addr_to_slab+0xd/0xb0
kernel: kasan_report+0xe1/0x120
kernel: ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel: ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel: kasan_check_range+0x11c/0x200
kernel: __asan_memcpy+0x3b/0x80
kernel: quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c]
kernel: ? __pfx_quicki2c_acpi_get_dsd_property.constprop.0+0x10/0x10 [intel_quicki2c]
kernel: quicki2c_get_acpi_resources+0x237/0x730 [intel_quicki2c]
[...]
kernel:
kernel:
kernel: The buggy address belongs to stack of task kworker/u33:2/75
kernel: an…
Source: NIST National Vulnerability Database NVD
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-2025-39809 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 8.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-39809" on the vendor's site.
CVE-2025-39809 (Linux kernel) — CWE-787 / CVSS v3 8.4
Attack vector: local / unauthenticated / 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.
Out-of-bounds write (CWE-787) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 8.4/10). 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
- BellSoft Alpaquita BELL-CVE-2025-39809 linux-lts Fixed in: 6.18.35-r1
- Debian DEBIAN-CVE-2025-39809 linux Fixed in: 6.16.5-1
- Ubuntu UBUNTU-CVE-2025-39809 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org