Versions of OpenPubkey library prior to 0.10.0 contained a vulnerability that would allow a specially crafted JWS to bypass signature verification. As OPKSSH depends on the OpenPubkey library for authentication, this vulnerability in OpenPubkey also applies to OPKSSH versions prior to 0.5.0 and would allow an attacker to bypass OPKSSH authentication.
CVE ID: CVE-2025-4658
CVSS Base Severity: CRITICAL
CVSS Base Score: 9.3
CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
Vendor: OPKSSH
Product: OPKSSH
EPSS Score: 0.03% (probability of being exploited)
EPSS Percentile: 6.02% (scored less or equal to compared to others)
EPSS Date: 2025-06-06 (when was this score calculated)