InDesign Desktop versions 21.1, 20.5.1 and earlier are affected by a Heap-based Buffer Overflow vulnerability that could result in application denial-of-service. An attacker could exploit this vulnerability to crash the application, causing disruption to services. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
Conclusion & alert: CVE-2026-21358 is rated Low Risk (23.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%).Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2026-21358
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).