CVE-2026-16477

Insecure Deserialization of .cleanshot Files in CleanShot X

HIGH
8.4
CVSS Score
Published: October 22, 2026 at 02:47 PM UTC
Updated: October 22, 2026 at 07:17 PM UTC
1 product affected across 1 vendorCleanShot X

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Severity
HIGH8.4
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

Third Party Advisory
Source: cverecord
https://cert.pl/en/posts/2026/10/CVE-2026-16477
Product
Source: cverecord
https://cleanshot.com/

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.4HIGHCERT-PL
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-502

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