CVE-2016-1819

Public exploit available. Not confirmed exploited in the wild yet. Fixed versions are out.

CVSS 3.07.8High EPSS percentile92nd4.8% chance in 30 days CISA KEVNot listedNo confirmed exploitation
Public exploit: 3 sources Fix5 products4 fixed builds listed below

Published 2016-05-20Updated 2026-05-06Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

Apple Iphone OsAffected: < 9.3.2Upgrade to: 9.3.2Stated by: NVD
Apple TvosAffected: < 9.2.1Upgrade to: 9.2.1Stated by: NVD
Apple Mac Os XAffected: < 10.11.5Upgrade to: 10.11.5Stated by: NVD
Apple WatchosAffected: < 2.2.1Upgrade to: 2.2.1Stated by: NVD
Apple Inc. OS XAffected: до 10.11.5Upgrade to: not statedStated by: BDU

Versions as the sources state them. Full version matrix after sign-in

Steps

Written by AI from the record

Check which Apple operating system versions your business devices are running (iOS, macOS/OS X, tvOS, watchOS).
If any devices are on iOS earlier than 9.3.2, upgrade iOS to 9.3.2 or newer.
If any devices are on macOS/OS X earlier than 10.11.5, upgrade OS X to 10.11.5 or newer.
If any devices are on tvOS earlier than 9.2.1, upgrade tvOS to 9.2.1 or newer.
If any devices are on watchOS earlier than 2.2.1, upgrade watchOS to 2.2.1 or newer.

Vendor advisory Usually a quick update

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

Use-after-free vulnerability in the IOAccelContext2::clientMemoryForType method 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 attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app, a different vulnerability than CVE-2016-1817 and CVE-2016-1818.

In plain language

Written by AI from the record

This Apple iOS/macOS/tvOS/watchOS bug can let a crafted app crash the device and, in some cases, run code with high privileges; if you’re still on very old OS versions, you should act.

CVE-2016-1819 is a use-after-free issue in Apple’s IOAccelContext2::clientMemoryForType (Apple graphics/memory handling), where a crafted app can trigger memory corruption that may lead to denial of service or arbitrary code execution in a privileged context on older iOS/tvOS/macOS/watchOS releases.

If you're affected

Device crashes and outages
High-privilege code execution
Data exposure from compromised device
Disruption to mobile workflows

What is it

This is a bug where the system reuses memory that was already freed, like putting a used label back on a box without checking it’s still the right one. A specially built app can use that mistake to crash the device or, more seriously, potentially run code with higher access than it should have.

Who is affected

This matters if your business uses devices running older Apple OS versions: iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, or watchOS before 2.2.1. The risk is primarily from a malicious or specially crafted app running on the device; if a device can’t reach those conditions (for example, it’s already on a fixed OS version), this issue shouldn’t apply.

How urgent is it

Treat this as important (AMBER): public exploit code exists, meaning attackers can turn this bug into real attacks rather than only theory. It’s not flagged as a CISA KEV item, but the combination of high impact (memory corruption/arbitrary code execution) and exploit availability makes upgrades the priority.

What to do — in detail

Confirm exposure

Inventory your in-use devices and record their OS versions:
- iOS versions
- macOS/OS X versions
- tvOS versions
- watchOS versions
If any device is on an affected range below, it is in scope:
- iOS < 9.3.2
- OS X/macOS < 10.11.5
- tvOS < 9.2.1
- watchOS < 2.2.1

Apply the fix (target versions)

Upgrade iOS to 9.3.2 or newer.
Upgrade OS X/macOS to 10.11.5 or newer.
Upgrade tvOS to 9.2.1 or newer.
Upgrade watchOS to 2.2.1 or newer.

Notes for rollout

Ensure devices have enough battery and stable network connectivity before upgrading.
After upgrading, re-check the OS version to confirm the device moved to a fixed release.

If upgrades can’t be done immediately

Reduce risk by limiting installation/execution of untrusted or unknown apps on the affected devices until you can upgrade.
Prioritize upgrading the devices most exposed to app browsing/installation in your business workflow.

What to monitor

After updates, watch for normal device stability and review any crash patterns you previously saw on the affected devices.
Maintain OS update discipline so this class of issue doesn’t reappear on legacy versions.

Technical context

CVE-2016-1819 is a use-after-free vulnerability (CWE-416) in Apple’s IOAccelContext2::clientMemoryForType. On older iOS/OS X/tvOS/watchOS versions, a crafted app can trigger memory corruption; this can result in denial of service (crashes) and, depending on circumstances, arbitrary code execution in a privileged context.

Findings indicate public exploit code exists (3 known). CISA KEV does not list this CVE. EPSS is provided as a prediction with a flat trend, but since exploitation is represented by public exploit availability, the practical risk is elevated even without KEV listing.

Exploit maturity: there is working public exploit material available, which generally increases real-world threat compared to vulnerabilities with only proof-of-concept code.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS92nd

Public exploit

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

3 sources with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in

EPSS

4.8% chance of exploitation activity in the next 30 days, which ranks it in the 92nd percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

A public exploit existed 61 days before the patch.

2026-09-23EPSS band changemoderate → 0epss band change
2026-09-21EPSS band change0 → moderateepss band change
2026-09-06EPSS band changemoderate → 0epss band change
2026-09-05EPSS band change0 → moderateepss band change
2026-08-31EPSS band changemoderate → 0epss band change
2026-08-29EPSS band changelow → moderate

Affected products

Apple Inc.commercial · USaka apple, apple computer
- iOSOSEmbeddedOperating Systems / mobile-os
- OS XOperating Systems
- tvosOSEmbeddedOperating Systems / mobile-os
- mac os xOSOn-premOperating Systems / unix-bsd
- watchosOSEmbeddedOperating Systems / mobile-os

And 2 more affected products. See all after sign-in

Technical detail

CVSS 3.0 vector

Open in the CVSS calculator

CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Scored 7.8 by NVD.

How it is reached

Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required NoneNo authentication required — anyone can exploit this
User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality HighTotal information disclosure — all data in the component is compromised
Integrity HighTotal loss of integrity — attacker can modify any data in the component
Availability HighTotal denial of service — the component is completely unavailable