How severe is CVE-2012-4559?

CVE-2012-4559 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2012-4559 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2012-4559?

CVE-2012-4559 primarily affects Libssh. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2012-4559?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2012-4559 published?

CVE-2012-4559 was published on 2012-11-30 and last updated on 2026-06-16.

CVE-2012-4559

CVE-2012-4559 is a medium-severity vulnerability in Libssh with a CVSS 2.0 base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-399.

Key facts

Severity: Medium (CVSS 2.0 base score 6.8)
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Libssh
Published: 2012-11-30
Last modified: 2026-06-16

Description

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.

Frequently asked questions

What is CVE-2012-4559?: 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.
How severe is CVE-2012-4559?: CVE-2012-4559 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2012-4559 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2012-4559?: CVE-2012-4559 primarily affects Libssh. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2012-4559?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2012-4559 published?: CVE-2012-4559 was published on 2012-11-30 and last updated on 2026-06-16.

References

Affected products (6)

cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:0.4.7:*:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:0.4.8:*:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:0.5.0:*:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:0.5.0:rc1:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:0.5.1:*:*:*:*:*:*:*

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