CVE-2023-32439
CVE-2023-32439 is a security flaw in Apple devices, the software on Apple’s iPhones, iPads and Macs. Attackers can run their own code on Apple devices. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 23 Jun 2023.[1]
Apple devices is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Fixed in version 15.7, 16.5 and 13.4.
Description
CISA calls it a webKit type confusion in Apple Multiple Products. In its words: “Apple iOS, iPadOS, macOS, and Safari WebKit contain a type confusion vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.”[1]
The underlying weakness is type confusion (CWE-843), in MITRE’s list of common software weaknesses.[2]
It scores 8.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| iOS and iPadOS | 15.7 |
| Safari | 16.5 |
| iOS and iPadOS | 16.5 |
| macOS | 13.4 |
Every device with Apple devices needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 23 Jun 2023, within a day of it being made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 14 Jul 2023 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 24%. That’s in the top 3% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Apple has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update Apple devices now.On iPhone and iPad: Settings, General, Software Update. On a Mac: System Settings, General, Software Update. Install it on every Apple device in the house. Then turn on automatic updates, so the next fix arrives on its own.
- Check you’re on 15.7 or later.Fixed in version 15.7, 16.5 and 13.4. Anything older is what attackers are going after.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 24%.[4] |
See also
Other Apple devices flaws
- CVE-2026-86950: out-of-bounds write ·
- CVE-2025-43520: classic buffer overflow ·
- CVE-2025-43510: improper locking ·
- CVE-2025-31277: buffer overflow ·
- CVE-2023-43000: use-after-free ·
- CVE-2021-30952: integer overflow or wraparound ·
Other type confusion flaws
- CVE-2026-85046, Chrome and other Chromium browsers: type confusion ·
- CVE-2026-21519, Microsoft Windows: type confusion ·
- CVE-2025-13223, Chrome and other Chromium browsers: type confusion ·
- CVE-2025-10585, Chrome and other Chromium browsers: type confusion ·
- CVE-2025-6554, Chrome and other Chromium browsers: type confusion ·
Added the same day
- CVE-2023-32435, Apple devices: webKit memory corruption ·
- CVE-2023-32434, Apple devices: integer overflow ·
- CVE-2023-27992, Zyxel Multiple Network-Attached Storage (NAS) Devices: multiple NAS devices command injection ·
- CVE-2023-20867, VMware Tools: authentication bypass ·
Every Apple flaw on CISA’s list · Everything added in June 2023
References
- ^ Cybersecurity and Infrastructure Security Agency. “Apple Multiple Products WebKit Type Confusion Vulnerability”. Known Exploited Vulnerabilities Catalog, added 23 Jun 2023.
- ^ National Institute of Standards and Technology. “CVE-2023-32439 Detail”. National Vulnerability Database, published 23 Jun 2023.
- ^ Apple. Advisories and fixes: support.apple.com, support.apple.com, support.apple.com, support.apple.com, support.apple.com, and 1 more on NVD’s record.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.240, percentile 97.8, 31 Oct 2026.
- CVE Program. “CVE-2023-32439”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.