Apple macOS: Arbitrary code execution via crafted file (out-of-bounds write)
Summary
A memory corruption issue in macOS allows processing of a maliciously crafted file to lead to arbitrary code execution. Apple describes it as an out-of-bounds write fixed with improved bounds checking, while NVD classifies it as CWE-125 (out-of-bounds read). The attack requires a user to open or process the crafted file, but no authentication, and the CVSS score is 8.8.
Affected
- macOS versions earlier than 15.8.2 (Sequoia), 26.7.2 (Tahoe) and 27 (Golden Gate), according to the CVE record
- Older macOS branches: Unknown.
Fixed in
- macOS Golden Gate 27
- macOS Sequoia 15.8.2
- macOS Tahoe 26.7.2
- Exact entry for CVE-2026-86929 in Apple's advisories: Not confirmed in the retrieved excerpts.
Workaround
Unknown. No vendor workaround published. The vendor fix is the mitigation.
Exploitation
- CISA SSVC: exploitation none, automatable no, total technical impact.
- Not listed in the CISA KEV catalog per the sources reviewed.
- Threat-intel aggregators report it as not known to be exploited.
- No public proof of concept found; this does not prove none exists.
Our recommendation
- Update all Macs to macOS Golden Gate 27, Sequoia 15.8.2 or Tahoe 26.7.2 as specified in Apple's advisories, with high priority.
- Verify the CVE entry in Apple's security advisories before reporting the fix as confirmed.
- Inventory Macs and confirm their installed macOS versions.
- Until patched, avoid opening unexpected attachments or downloads and keep Gatekeeper and XProtect enabled.
- Monitor for signs of exploitation and for updates to CISA KEV.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Apple Security Content macOS Golden Gate 27 support.apple.com
- Apple Security Content macOS Tahoe 26.7.2 support.apple.com
- Apple Security Content macOS Sequoia 15.8.2 support.apple.com
- OpenCVE CVE-2026-86929 app.opencve.io
- VulDB CVE-2026-86929 vuldb.com
- Strix CVE-2026-86929 www.strix.ai
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 31 Oct 2026, 10:23.
Original description (NVD)
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2. Processing a maliciously crafted file may lead to arbitrary code execution.
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.