CVE-2026-58051

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc	Broken Link
https://github.com/libssh2/libssh2/blob/master/src/publickey.c	Product
https://www.vulncheck.com/advisories/libssh2-free-of-uninitialized-pointer-in-publickey-list-cleanup	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:*

History

30 Jun 2026, 17:42

Type	Values Removed	Values Added
CPE		cpe:2.3:a:libssh2:libssh2::::::::
First Time		Libssh2 libssh2 Libssh2
References	~~() https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc -~~	() https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc - Broken Link
References	~~() https://github.com/libssh2/libssh2/blob/master/src/publickey.c -~~	() https://github.com/libssh2/libssh2/blob/master/src/publickey.c - Product
References	~~() https://www.vulncheck.com/advisories/libssh2-free-of-uninitialized-pointer-in-publickey-list-cleanup -~~	() https://www.vulncheck.com/advisories/libssh2-free-of-uninitialized-pointer-in-publickey-list-cleanup - Third Party Advisory

28 Jun 2026, 02:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-28 02:16

Updated : 2026-06-30 17:42

NVD link : CVE-2026-58051

Mitre link : CVE-2026-58051

CVE.ORG link : CVE-2026-58051

JSON object : View

Products Affected

libssh2

libssh2

CWE

CWE-908

Use of Uninitialized Resource

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