Samsung Bixby: Improper input validation allows local arbitrary activity launch
Summary
Samsung Bixby versions prior to 4.0.85.6 contain an improper input validation flaw. A privileged local attacker can use it to launch arbitrary activities within Bixby's scope. The attack requires an existing privileged foothold on the device, so the risk for most SMEs is low. Samsung's bulletin labels this issue CVE-2026-21056, so the CVE ID mapping still needs to be verified.
Affected
- Samsung Bixby prior to 4.0.85.6
- Some secondary sources list other or all versions; the vendor threshold of 4.0.85.6 is used here.
Fixed in
- Update Bixby to version 4.0.85.6 or later (Samsung advisory, October 2026)
- Install the current Samsung monthly security update
Workaround
Unknown. No vendor workaround was found; apply the patch.
Exploitation
- No evidence of exploitation in the wild.
- Not listed in CISA KEV.
- No public proof of concept found.
- VulDB flags the entry as 0-Day, which is a status flag and not confirmed exploitation.
Our recommendation
- Check the Bixby version on managed Galaxy devices and target 4.0.85.6 or later.
- Confirm that the Samsung October 2026 security patch level is installed.
- Verify the CVE ID mapping (CVE-2026-21056 vs. CVE-2026-21157) with Samsung or NVD before reporting to clients.
- Enforce update compliance via MDM where possible.
- Recheck CISA KEV and public PoC listings in about two weeks.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Samsung Mobile Security bulletin (OCT-2026) security.samsungmobile.com
- VulDB entry CVE-2026-21157 vuldb.com
- VulDB CVE page vuldb.com
- threatint CVE record cve.threatint.com
- OffSeq threat radar entry radar.offseq.com
- Strix CVE entry www.strix.ai
- CVE Daily Brief (29 Oct batch) github.com
- APKMirror Bixby 4.0.85.6 release www.apkmirror.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 1 Nov 2026, 13:04.
Original description (NVD)
Improper input validation in Bixby prior to version 4.0.85.6 allows privileged local attackers to launch arbitrary activity.
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.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.