· 1 CVE

macOS Sequoia 15.3.1 Security Update

macOS Sequoia 15.3.1 fixes 1 vulnerability, and Apple says one may have been exploited. Every fix, in Apple's words, with what it could have allowed.

Actively exploited — update now

What macOS Sequoia 15.3.1 Fixes

macOS Sequoia 15.3.1, released February 10, 2025, fixes 1 vulnerability in 1 part of the system, according to Apple's security advisory.

Apple says one of these flaws — CVE-2025-43200 — may already have been exploited. That makes macOS Sequoia 15.3.1 an update to install now rather than at the weekend.

It has since been superseded: the newest security release for macOS Sequoia is macOS Sequoia 15.8.2, from October 26, 2026, which includes these fixes.

What an attacker could doFixes
Other1

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.

  • Messages Exploited

    A logic issue existed when processing a maliciously crafted photo or video shared via an iCloud Link. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals.

    This issue was addressed with improved checks.

    CVE-2025-43200

Which Devices Get macOS Sequoia 15.3.1

Apple lists macOS Sequoia 15.3.1 for: macOS Sequoia.

How to Install macOS Sequoia 15.3.1

On the Mac, open System Settings → General → Software Update. Macs that cannot run the newest macOS are offered the update for their own version there.

Security fixes are cumulative: any later release for the same version includes these as well, so if you are already past macOS Sequoia 15.3.1 there is nothing to do.

Every Fix in macOS Sequoia 15.3.1

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.

    macOS Sequoia Security Release History

    macOS Sequoia 15.3.1 in context: the security releases Apple has published for macOS Sequoia, newest first, with the number of fixes each carried.

    ReleaseReleasedFixes
    macOS Sequoia 15.6July 29, 202592
    macOS Sequoia 15.5May 12, 202554
    macOS Sequoia 15.4.1April 16, 20252 Exploited
    macOS Sequoia 15.4March 31, 2025165
    macOS Sequoia 15.3.2March 11, 20251 Exploited
    macOS Sequoia 15.3.1February 10, 20251 Exploited
    macOS Sequoia 15.3January 27, 202572
    macOS Sequoia 15.2December 11, 202483
    macOS Sequoia 15.1.1November 19, 20242
    macOS Sequoia 15.1October 28, 202482
    macOS Sequoia 15September 16, 2024103

    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 macOS Sequoia 15.3.1 fix?

    1 security vulnerability in 1 part of the system, from Apple's advisory of February 10, 2025.

    Was anything fixed in macOS Sequoia 15.3.1 exploited?

    Yes. Apple says CVE-2025-43200 may have been exploited before the fix. Install it now.

    Which devices can install macOS Sequoia 15.3.1?

    macOS Sequoia.

    Is macOS Sequoia 15.3.1 the latest security update?

    No. macOS Sequoia 15.8.2, from October 26, 2026, is newer and includes these fixes.

    Source: About the security content of macOS Sequoia 15.3.1, Apple. Rechecked automatically while Apple is still adding entries.

    Every Apple security update