CVE-2026-89436: Linux kernel · platform/x86: panasonic-laptop: Fix sentinel write past pcc->sinf[]
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 12 Nov 2026, 20:26 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available that modifies the driver to skip the sentinel write when there is no room, preventing the heap overflow while maintaining compatibility with affected hardware. Users should apply the updated Linux kernel versions that include this patch. No additional mitigation is required as the fix addresses the root cause without breaking functionality.
Description
CVE-2026-89436 is a high-severity vulnerability in the Linux kernel's panasonic-laptop ACPI driver affecting certain kernel versions. It involves a heap overflow caused by writing a sentinel value past the allocated array bounds in the acpi_pcc_retrieve_biosdata() function. The issue arises from an off-by-one error related to handling SINF package counts, which can lead to a 4-byte heap overflow on affected hardware. The vulnerability has a CVSS score of 7.8 and impacts confidentiality, integrity, and availability. A fix has been implemented to skip the sentinel write when there is no room, avoiding the overflow without breaking hardware compatibility.
References
- ubuntu.com/security/CVE-2026-89436 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89436 (opens in a new tab)
- git.kernel.org/linus/329f10d8be193bf36af124e00b9dd6644cd71724 (opens in a new tab)
- git.kernel.org/stable/c/329f10d8be193bf36af124e00b9dd6644cd71724 (opens in a new tab)
- git.kernel.org/stable/c/a93df956ee4d903735b6d395362c839cb1dc07e3 (opens in a new tab)