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Mallory
High

Out-of-bounds write in Apple Quick Look file parsing

IdentifiersCVE-2026-43656CWE-787· Out-of-bounds Write

CVE-2026-43656 is an out-of-bounds write vulnerability in Apple Quick Look. According to the provided Apple security advisory content, the flaw is triggered when Quick Look parses a maliciously crafted file. Apple states the issue was addressed through improved input validation. Successful triggering leads to memory corruption manifested as unexpected app termination. The issue is 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, and macOS Tahoe 26.5.

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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.

Parsing a maliciously crafted file may cause unexpected app termination, resulting in a denial-of-service condition in the affected Quick Look parsing context. The provided content does not state confirmed code execution or privilege escalation for this CVE.

Mitigation

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

Until patches are applied, reduce exposure by avoiding opening or previewing untrusted files through Quick Look or applications that invoke Quick Look parsing automatically. Limit handling of externally supplied files from untrusted sources where operationally feasible. No vendor-specific workaround beyond updating is provided in the supplied content.

Remediation

Patch, then assume compromise.

Upgrade affected Apple platforms to a fixed release: iOS 18.7.9, iPadOS 18.7.9, iOS 26.5, iPadOS 26.5, macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, or macOS Tahoe 26.5, as applicable. Apple indicates the vulnerability was remediated with improved input validation in Quick Look.
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

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What this page doesn’t show

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Exposure mapping

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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 activity3

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