All vulnerabilities
CVE-2026-16477

Insecure Deserialization of .cleanshot Files in CleanShot X

MTW CleanShot X
Open in ThreatlineRecord JSON
CVSS
8.4High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.29%Chance of exploitation activity in the next 30 days, higher than 20% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in4.5.2Also 4.6.3, 4.7.8 and 1 moreCVE List
Published22 Oct 2026Updated 22 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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

Text from CVE List

Affected versions 4

  • CleanShot Xaffected: 4.0.0 before 4.5.2CVE List
  • CleanShot Xaffected: 4.6.0 before 4.6.3CVE List
  • CleanShot Xaffected: 4.7.0 before 4.7.8CVE List
  • CleanShot Xaffected: 4.8.0 before 4.8.10CVE List

References 2