openrsync through 0.5.0, as used in OpenBSD through 7.8 and on other platforms, allows a client to cause a server SIGSEGV by specifying a length of zero for block data, because the relationship between p->rem and p->len is not checked.
Conclusion & alert: CVE-2025-67901 is rated Low Risk (26.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.24%).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-2025-67901
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).