Apple Xcode: Sandbox escape due to missing library validation
Summary
Apple Xcode before version 27 contains a flaw in which library validation is not enforced on some affected binaries. A malicious app running on the same Mac may be able to break out of its sandbox. The attacker needs local access and low privileges, and the attack requires a malicious app to run on the system.
Affected
- Apple Xcode versions before 27 (CNA record: affected 0 to < 27)
- Vendor advisory: Xcode available for macOS Tahoe 26.6 and later
Fixed in
- Apple Xcode 27 (advisory released September 14, 2026)
- Backports to older Xcode branches: Unknown.
Workaround
No workaround is documented by the vendor. The fix is the update to Xcode 27.
- Until systems are updated, do not install or run untrusted apps or unverified development tools on Macs with Xcode.
Exploitation
- No public exploit or proof of concept is known.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- Not listed in the CISA KEV catalog (per Strix).
- EPSS score 0.00146 (per Vulners).
Our recommendation
- Inventory Macs with Xcode installed.
- Update Xcode to version 27 on macOS Tahoe 26.6 or later.
- Enforce a policy for installing and running unvetted developer tools and apps.
- Verify the CVSS score against the NVD record, because VulDB rates the issue lower (4.8) and lists it as affected up to version 26.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Apple Support: About the security content of Xcode 27 support.apple.com
- VulDB: CVE-2026-86949 vuldb.com
- OpenCVE: CVE-2026-86949 app.opencve.io
- Vulners VulnRichment: CVE-2026-86949 vulners.com
- Strix: CVE-2026-86949 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, 15:37.
Original description (NVD)
This issue was addressed by enforcing library validation on the affected binaries. This issue is fixed in Xcode 27. A malicious app may be able to break out of its sandbox.
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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