CVE-2015-2157: The (1) ssh2_load_userkey and (2) ssh2_save_userkey functions in PuTTY 0.51 through 0.63 do not properly wi...

Security readout for executives and security teams

CVE-2015-2157 affects PuTTY versions 0.51 through 0.63. PuTTY did not fully erase SSH-2 private keys from memory after loading or saving them. A local user able to read memory could recover sensitive key material, potentially enabling later unauthorized SSH access. Exposure is most likely on endpoints, jump hosts, or administrator workstations running PuTTY 0.51 through 0.63. Risk increases on shared systems or systems where malware, local users, crash dumps, or memory inspection tools could access PuTTY process memory. Treat as a focused remediation item for systems that handle privileged SSH access. It is not documented as remotely exploitable, but leaked private keys can create broader compromise paths if exposed on shared or infected machines. Mitigation focus: Identify and upgrade PuTTY installations older than or equal to 0.63.; Use vendor or distribution-fixed PuTTY packages from trusted repositories.; Review Debian, Fedora, openSUSE, and PuTTY guidance for affected package status..

Prepared

Jun 14, 2026, 05:11 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.