Google Android: Out-of-bounds write in Keymaster enables local privilege escalation
Summary
A missing bounds check in km_read_data_response in keymaster.c allows an out-of-bounds write on the heap. A local attacker who already holds System-level privileges can use this to escalate privileges further. No user interaction is required. Google rates the issue High in its Pixel Update Bulletin for November 2026, and NVD analysis was still pending at the time of writing.
Affected
- Google Pixel devices with a security patch level below 2026-11-05
- Exact affected Android build numbers: Unknown.
- Note: the CNA record lists the affected item as Android kernel, while the Pixel bulletin places the issue under the Bootloader subcomponent. This discrepancy is unresolved.
Fixed in
- Security patch level 2026-11-05 or later (Pixel Update Bulletin, November 2026)
Workaround
Unknown. No workaround was found; the remedy is the patch.
Exploitation
- No known exploitation as of 10 November 2026.
- No public proof of concept reported. No CISA KEV listing found in the sources checked.
- CISA SSVC assessment: Exploitation none, Automatable no, Technical Impact total.
Our recommendation
- Check the patch level of managed Pixel devices (Settings > About phone > Android security update).
- Install the 2026-11-05 patch level or later as soon as it is available to your devices.
- Prioritise company and BYOD Pixel devices that handle sensitive data.
- Keep app-installation controls in place via your mobile device management, since an attacker would first need a foothold on the device.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Google Pixel Update Bulletin, November 2026 source.android.com
- CVE Record CVE-2026-55346 www.cve.org
- OSV entry PUB-A-511631506 osv.dev
- OffSeq threat radar: CVE-2026-55346 radar.offseq.com
- Strix: CVE-2026-55346 www.strix.ai
- 9to5Google: Android 17 QPR2 November Pixel update 9to5google.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 11:27.
Original description (NVD)
In km_read_data_response of keymaster.c, there is a possible way to trigger an out of bounds write on the heap due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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