CVE-2026-16477

Insecure Deserialization of .cleanshot Files in CleanShot X

Published Oct 22, 2026 CVSS 4.0 · 8.4 High EPSS < 1% KEV · Not listed
Description
CleanShot X for macOS insecurely deserializes untrusted data embedded in a .cleanshot project file (editable screenshot annotations). Exploitation requires an attacker to craft a malicious .cleanshot file, deliver it to the target, and have the target open it; the payload then executes automatically during parsing, resulting in arbitrary code execution in the context of the current user. Users who have never opened a .cleanshot file from an untrusted source are not affected by this vulnerability. This vulnerability was fixed in versions: 4.5.2, 4.6.3, 4.7.8 and 4.8.10

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description CleanShot X for macOS insecurely deserializes untrusted data embedded in a .cleanshot project file (editable screenshot annotations). Exploitation requires an attacker to craft a malicious .cleanshot file, deliver it to the target, and have the target open it; the payload then executes automatically during parsing, resulting in arbitrary code execution in the context of the current user. Users who have never opened a .cleanshot file from an untrusted source are not affected by this vulnerability. This vulnerability was fixed in versions: 4.5.2, 4.6.3, 4.7.8 and 4.8.10
Title Insecure Deserialization of .cleanshot Files in CleanShot X
First Time appeared Mtw
Mtw cleanshot X
Weaknesses CWE-502
CPEs cpe:2.3:a:mtw:cleanshot_x:*:*:macos:*:*:*:*:*
Vendors & Products Mtw
Mtw cleanshot X
References
Metrics cvssV4_0

{'score': 8.4, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
CERT-PL
Published
Updated
Oct 22, 2026, 7:00 PM
Reserved
Jul 21, 2026, 2:22 PM
Status
Awaiting Analysis
Published
Oct 22, 2026, 3:17 PM
Modified
Oct 22, 2026, 7:17 PM