What is CVE-2016-4448?

CVE-2016-4448 is a critical-severity vulnerability in Apple Icloud, classified under Use of Externally-Controlled Format String. CVSS score: 9.8/10. Published 2016-06-09.

How severe is CVE-2016-4448?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2016-4448 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Apple Icloud

CVE-2016-4448

Format string vulnerability in libxml2 before 2.9.4 allows attackers to have unspecified impact via format string specifiers in unknown vectors.

Published 2016-06-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.070 (94.1th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 94.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.070 · newest: 0.070 · change: 0.000

Affected products

Apple Icloud
Apple Iphone OS
Apple Itunes
Apple Mac OS X
Apple tvOS
Apple watchOS
HP Icewall Federation Agent — versions 3.0
Mcafee Web Gateway
Microsoft Windows
Oracle Linux — versions 6, 7

Weakness classification (CWE)

CWE-134 — Use of Externally-Controlled Format String

Public proof-of-concept exploits

akaganeite/CVE4PP

References

www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html (Vendor Advisory)
kc.mcafee.com/corporate/index (Third Party Advisory)
www.slackware.com/security/viewer.php (vendor-advisory, Third Party Advisory)
access.redhat.com/errata/RHSA-2016:1292 (vendor-advisory, Third Party Advisory)
www.openwall.com/lists/oss-security/2016/05/25/2 (mailing-list, Mailing List, Third Party Advisory)
www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html (Third Party Advisory)
www.securityfocus.com/bid/90856 (VDB Entry, Third Party Advisory, vdb-entry)
git.gnome.org/browse/libxml2/commit/ (Vendor Advisory)
lists.apple.com/archives/security-announce/2016/Jul/msg00003.html (vendor-advisory, Mailing List, Release Notes)
lists.apple.com/archives/security-announce/2016/Jul/msg00002.html (vendor-advisory, Mailing List, Release Notes)

Frequently asked questions

What is CVE-2016-4448?: CVE-2016-4448 is a critical-severity vulnerability in Apple Icloud, classified under Use of Externally-Controlled Format String. CVSS score: 9.8/10. Published 2016-06-09.
How severe is CVE-2016-4448?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2016-4448 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.