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Mallory
Medium

Denial-of-service in macOS WindowServer cache handling

IdentifiersCVE-2026-20602CWE-400· Uncontrolled Resource Consumption

CVE-2026-20602 is a cache-handling flaw in Apple macOS WindowServer. Apple indicates the issue was addressed with improved handling of caches. A malicious app may be able to trigger the condition to cause a denial-of-service. The issue is fixed in macOS Sequoia 15.7.4, macOS Tahoe 26.3, and macOS Sonoma 14.8.4.

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Are you exposed to this one?

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Denial-of-service: a local application can cause WindowServer to become unavailable or unstable, resulting in loss of GUI/session availability and disruption of normal system operation.

Mitigation

If you can’t patch tonight, do this now.

No vendor workaround is described in the provided content. Operationally, reduce exposure by restricting execution of untrusted/local apps (application allowlisting, least privilege, MDM controls) until the relevant macOS updates can be deployed.

Remediation

Patch, then assume compromise.

Update to a fixed macOS release: macOS Sequoia 15.7.4, macOS Tahoe 26.3, or macOS Sonoma 14.8.4 (or later) per Apple’s security advisories.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
AppleMacosoperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

5 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity4

Community discussion across Reddit, Mastodon, and other social sources.