High severity · published Oct 22, 2026
CVE-2026-16477
Insecure Deserialization of .cleanshot Files in CleanShot X
8.4
CVSS
0.3%
EPSS
No
On KEV
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
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CX
CleanShot X · MTW
4.0.0 before 4.5.2; 4.6.0 before 4.6.3; 4.7.0 before 4.7.8; 4.8.0 before 4.8.10 · source: vendor