High severity · published Jun 28, 2026
CVE-2026-58050
libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
libssh2 · libssh2
through 1.11.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-58050
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-58050
Broken Link
https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc
Product
https://github.com/libssh2/libssh2/blob/master/src/publickey.c
Third Party Advisory
https://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation
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