CVE-2026-58050

HIGH 7.0

libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation

CVSS Score

7.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-190
Vendor	libssh2
Product	libssh2
Published	Jun 28, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

High

Affected Versions

libssh2 / libssh2

0 ≤ 1.11.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc github.com: https://github.com/libssh2/libssh2/blob/master/src/publickey.c vulncheck.com: https://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation

Credits

ashdfrkl