What Safari 18.3.1 Fixes
Safari 18.3.1, released March 11, 2025, fixes 1 vulnerability in 1 part of the system, according to Apple's security advisory.
Apple says one of these flaws — CVE-2025-24201 — may already have been exploited. That makes Safari 18.3.1 an update to install now rather than at the weekend.
It has since been superseded: the newest security release for Safari is Safari 27.2, from October 26, 2026, which includes these fixes.
| What an attacker could do | Fixes |
|---|---|
| Elevated privileges or sandbox escape | 1 |
Grouped by us from the impact Apple gives for each fix; the impact lines below are Apple's own.
Exploited Before the Fix
Apple flags a fix as possibly exploited when it has a credible report that the flaw was used against real people before the patch. This one is the reason to update today.
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WebKit Exploited
Maliciously crafted web content may be able to break out of Web Content sandbox. This is a supplementary fix for an attack that was blocked in iOS 17.2. (Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals on versions of iOS before iOS 17.2.)
An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions.
CVE-2025-24201
Which Devices Get Safari 18.3.1
Apple lists Safari 18.3.1 for: macOS Ventura and macOS Sonoma.
How to Install Safari 18.3.1
Safari updates arrive through Software Update on the Mac. On a current macOS they are part of the macOS update; on older versions they are offered separately.
Security fixes are cumulative: any later release for the same version includes these as well, so if you are already past Safari 18.3.1 there is nothing to do.
Every Fix in Safari 18.3.1
The rest of Apple's advisory — every fix not already listed above, the most serious kinds first. Each entry is the part of the system affected, Apple's description of the impact and the fix, and the CVE ID.
Safari Security Release History
Safari 18.3.1 in context: the security releases Apple has published for Safari, newest first, with the number of fixes each carried.
| Release | Released | Fixes |
|---|---|---|
| Safari 26.1 | November 3, 2025 | 21 |
| Safari 26 | September 15, 2025 | 9 |
| Safari 18.6 | July 30, 2025 | 17 |
| Safari 18.5 | May 12, 2025 | 11 |
| Safari 18.4 | March 31, 2025 | 14 |
| Safari 18.3.1 | March 11, 2025 | 1 Exploited |
| Safari 18.3 | January 27, 2025 | 8 |
| Safari 18.2 | December 11, 2024 | 8 |
| Safari 18.1.1 | November 19, 2024 | 2 |
| Safari 18.1 | October 29, 2024 | 5 |
| Safari 18 | September 16, 2024 | 7 |
The Same Fixes Elsewhere
Apple ships most fixes to every platform that shares the code, and to older versions still under support. These releases close at least one of the same CVEs:
Frequently Asked Questions
What does Safari 18.3.1 fix?
1 security vulnerability in 1 part of the system, from Apple's advisory of March 11, 2025.
Was anything fixed in Safari 18.3.1 exploited?
Yes. Apple says CVE-2025-24201 may have been exploited before the fix. Install it now.
Which devices can install Safari 18.3.1?
macOS Ventura and macOS Sonoma.
Is Safari 18.3.1 the latest security update?
No. Safari 27.2, from October 26, 2026, is newer and includes these fixes.
Source: About the security content of Safari 18.3.1, Apple. Rechecked automatically while Apple is still adding entries.