All vulnerabilities
CVE-2026-86871

An integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker with control of a network file server

Apple macOSOperating systems
Open in ThreatlineRecord JSON
CVSS
5.9Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.40%Chance of exploitation activity in the next 30 days, higher than 33% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in15.8Also 26.7, 27CVE List
Published20 Oct 2026Updated 20 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

An integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker with control of a network file server may be able to cause unexpected system termination.

Text from CVE List

Affected versions 3

  • macOSaffected: all versions before 15.8CVE List
  • macOSaffected: all versions before 26.7CVE List
  • macOSaffected: all versions before 27CVE List

References 3