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Mallory
Medium

Sensitive data leak via malicious website in Apple zlib

IdentifiersCVE-2026-28920CWE-200· Exposure of Sensitive Information…

CVE-2026-28920 is an information disclosure vulnerability in Apple platforms, attributed in the provided advisories to zlib. Apple states that the issue was addressed with additional validation. Successful exploitation occurs when a user visits a maliciously crafted website, which can trigger leakage of sensitive data. The issue is listed as fixed in iOS 18.7.9 and iPadOS 18.7.9, iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, and watchOS 26.5. No further technical detail about the precise vulnerable function or code path is provided in the supplied content.

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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.

Visiting attacker-controlled web content may cause sensitive data to be disclosed from the affected process or platform context. Based on the supplied advisories, the demonstrated impact is information leakage rather than code execution or privilege escalation.

Mitigation

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

Until patched, reduce exposure to untrusted web content, especially attacker-supplied links or websites. Limiting browsing from affected devices and using only trusted sites may reduce risk, but no complete vendor-endorsed workaround is provided in the supplied content.

Remediation

Patch, then assume compromise.

Apply the vendor fixes provided by Apple: iOS 18.7.9 and iPadOS 18.7.9, iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, and watchOS 26.5. Apple indicates the issue was remediated through additional validation.
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
AppleIosoperating_system
AppleIpadosoperating_system
AppleIphone Osoperating_system
AppleMacosoperating_system
AppleTvosoperating_system
AppleVisionosoperating_system
AppleWatchosoperating_system

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What this page doesn’t show

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Exposure mapping

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Threat actor evidence

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Associated malware

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Detection signatures

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Vendor-by-vendor mapping

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

Social activity8

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