CVE-2016-1840

Severity: high (CVSS 7.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2016-05-20 · updated 2026-06-17
Weakness: CWE-119

Description

Heap-based buffer overflow in the xmlFAParsePosCharGroup function in libxml2 before 2.9.4, as used in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted XML document.

Affected products

Apple Iphone Os: before 9.3.2 — fixed in 9.3.2
macOS: before 10.11.5 — fixed in 10.11.5
Apple tvOS: before 9.2.1 — fixed in 9.2.1
Apple watchOS: before 2.2.1 — fixed in 2.2.1
Canonical Ubuntu Linux: 12.04, 14.04, 15.10, 16.04
Debian Linux: 8.0
McAfee Web Gateway (MWG): from 7.5.0.0 through 7.5.2.10; from 7.6.0.0 through 7.6.2.3
RedHat Enterprise Linux Desktop: 6.0, 7.0
RedHat Enterprise Linux Server: 6.0, 7.0
RedHat Enterprise Linux Server Aus: 7.2, 7.3, 7.4, 7.6
RedHat Enterprise Linux Server Eus: 7.2, 7.3, 7.4, 7.5, 7.6
RedHat Enterprise Linux Server Tus: 7.2, 7.3, 7.6
RedHat Enterprise Linux Workstation: 6.0, 7.0
xmlsoft libxml2: before 2.9.4 — fixed in 2.9.4

How to fix

Upgrade to a fixed version: Apple Iphone Os 9.3.2; macOS 10.11.5; Apple tvOS 9.2.1; Apple watchOS 2.2.1; xmlsoft libxml2 2.9.4. Check the vendor advisory for mitigations.

References

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