Multiple double free vulnerabilities in the (1) agent_sign_data function in agent.c, (2) channel_request function in channels.c, (3) ssh_userauth_pubkey function in auth.c, (4) sftp_parse_attr_3 function in sftp.c, and (5) try_publickey_from_file function in keyfiles.c in libssh before 0.5.3 allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors.
Conclusion & alert: CVE-2012-4559 is rated Moderate Risk (59.3/100): CVSS Medium severity, with high exploitation likelihood (EPSS 5.18%, 91th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 5.04% | 5.18% | +0.14% |
| 2 | 2025-11-16 | 3.82% | 5.04% | +1.22% |
| 3 | 2025-03-30 | — | 3.82% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2012-4559 not yet assigned priority: Debian including 1 source packages (libssh), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2012-4559 |
gentoo
|
normal | CVE-2012-4559: 1 GLSA(s) (201402-26), 1 atom(s) (net-libs/libssh); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2012-4559 |
suse
|
medium | CVE-2012-4559 severity moderate: SUSE including 36 source package names (libssh, libssh-config-0.10.6-1.12, …), 65 product×package rows across 29 product lines (SUSE Linux Enterprise Desktop 12, SUSE Linux Enterprise Desktop 12 SP1, … (29 product lines)): Fixed 52, Known Not Affected 13. | https://www.suse.com/security/cve/CVE-2012-4559/ |
ubuntu
|
low | CVE-2012-4559 low priority: Ubuntu including 1 source packages (libssh), 6 status rows across 6 suites (hardy, lucid, oneiric, precise, quantal, upstream): released 5, ignored 1. | https://ubuntu.com/security/CVE-2012-4559 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| libssh | libssh | <= 0.5.2 | cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* |
| libssh | libssh | 0.4.7 | cpe:2.3:a:libssh:libssh:0.4.7:*:*:*:*:*:*:* |
| libssh | libssh | 0.4.8 | cpe:2.3:a:libssh:libssh:0.4.8:*:*:*:*:*:*:* |
| libssh | libssh | 0.5.0 | cpe:2.3:a:libssh:libssh:0.5.0:*:*:*:*:*:*:* |
| libssh | libssh | 0.5.0 | cpe:2.3:a:libssh:libssh:0.5.0:rc1:*:*:*:*:*:* |
| libssh | libssh | 0.5.1 | cpe:2.3:a:libssh:libssh:0.5.1:*:*:*:*:*:*:* |