CVE-2026-58050
libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation
- State
- Published
- Severity
- 8.3 High
- Published
- Jun 28, 2026
- Updated
- Jun 29, 2026
- Reserved
- Jun 28, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.3 High | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 7.0 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H | VulnCheck |
Weaknesses
- CWE-190 Integer Overflow or Wraparound
Affected Products
| Product | Versions |
|---|---|
libssh2libssh2 |
|
References
- Proof of Conceptexploitthird-party-advisory
- src/publickey.cproduct
- VulnCheck Advisory: libssh2 - Integer Overflow in publickey Subsystem Attribute Allocationthird-party-advisory
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