Vulnerability · Published May 13, 2025 · Assigned by cloudflare
CVE-2025-4658Authentication Bypass in OPKSSH
Critical 9.3
In plain English
A critical-severity security flaw in OPKSSH from OPKSSH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/openpubkey/opkssh | 0.5.0 | GHSA-56wx-66px-9j66 |
| Go | github.com/openpubkey/opkssh | 0.5.0 | GO-2025-3680 |
| Ubuntu:25.10 | opkssh | no fix listed | UBUNTU-CVE-2025-4658 |
| Ubuntu:26.10 | opkssh | no fix listed | UBUNTU-CVE-2025-4658 |
Affected products (as reported)
Weakness: CWE-305 · 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