CVE-2026-58051
MEDIUM
6.5
CVSS 3.1
Description
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.
Metadata
Severity & Metrics
6.5
MEDIUM CVSS 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| libssh2 | libssh2 | — | 0 ≤ 1.11.1 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-908 | cna | Use of Uninitialized Resource |
CVSS scores (2)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 8.3 | HIGH | 4.0 | cna | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N |
| 6.5 | MEDIUM | 3.1 | cna | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H |
References (3)
- Proof of Concept https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc
- src/publickey.c https://github.com/libssh2/libssh2/blob/master/src/publickey.c
- VulnCheck Advisory: libssh2 - Free of Uninitialized Pointer in publickey List Cleanup https://www.vulncheck.com/advisories/libssh2-free-of-uninitialized-pointer-in-publickey-list-cleanup