# CVE-2026-58051: libssh2: libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before par...

CVE-2026-58051 is fixed in 8 products on 1 platform, first by DEBIAN-CVE-2026-58051, released June 28, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-58051
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0028
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 27, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libssh2 Debian 12.15 (bookworm) | 1.10.0-3+deb12u1 | [DEBIAN-CVE-2026-58051](https://patchblox.com/security/data/fix/linux/debian-cve-2026-58051.md) | Jun 28, 2026 |
| Linux | libssh2 Debian 13.5 (trixie) | 1.11.1-1+deb13u2 | [DEBIAN-CVE-2026-58051](https://patchblox.com/security/data/fix/linux/debian-cve-2026-58051.md) | Jun 28, 2026 |
| Linux | libssh2 Debian 14 | 1.11.1-6 | [DEBIAN-CVE-2026-58051](https://patchblox.com/security/data/fix/linux/debian-cve-2026-58051.md) | Jun 28, 2026 |
| Linux | libssh2 amzn 2023 | 1.10.0-1.amzn2023.0.5 | [ALAS2023-2026-1966](https://patchblox.com/security/data/fix/linux/alas2023-2026-1966.md) | Jul 20, 2026 |
| Linux | libssh2-1 Ubuntu 18.04.6 LTS (bionic) | 1.8.0-1ubuntu0.1+esm1 | [libssh2-1 1.8.0-1ubuntu0.1+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libssh2-1-1.8.0-1ubuntu0.1-esm1.md) | Jul 24, 2026 |
| Linux | libssh2-1 Ubuntu 20.04 LTS (focal) | 1.8.0-2.1ubuntu0.1+esm1 | [libssh2-1 1.8.0-2.1ubuntu0.1+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libssh2-1-1.8.0-2.1ubuntu0.1-esm1.md) | Jul 24, 2026 |
| Linux | libssh2-1 Ubuntu 22.04.1 LTS (jammy) | 1.10.0-3ubuntu0.1 | [libssh2-1 1.10.0-3ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libssh2-1-1.10.0-3ubuntu0.1.md) | Jul 24, 2026 |
| Linux | libssh2-1t64 Ubuntu 24.04.5 LTS (noble) | 1.11.0-4.1ubuntu0.24.04.3 | [libssh2-1t64 1.11.0-4.1ubuntu0.24.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libssh2-1t64-1.11.0-4.1ubuntu0.24.04.3.md) | Jul 14, 2026 |
| Linux | libssh2-1t64 Ubuntu 26.04.1 LTS (resolute) | 1.11.1-1ubuntu0.26.04.3 | [libssh2-1t64 1.11.1-1ubuntu0.26.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libssh2-1t64-1.11.1-1ubuntu0.26.04.3.md) | Jul 24, 2026 |
| Linux | libssh2-debuginfo amzn 2023 | 1.10.0-1.amzn2023.0.5 | [ALAS2023-2026-1966](https://patchblox.com/security/data/fix/linux/alas2023-2026-1966.md) | Jul 20, 2026 |
| Linux | libssh2-debugsource amzn 2023 | 1.10.0-1.amzn2023.0.5 | [ALAS2023-2026-1966](https://patchblox.com/security/data/fix/linux/alas2023-2026-1966.md) | Jul 20, 2026 |
| Linux | libssh2-devel amzn 2023 | 1.10.0-1.amzn2023.0.5 | [ALAS2023-2026-1966](https://patchblox.com/security/data/fix/linux/alas2023-2026-1966.md) | Jul 20, 2026 |
| Linux | libssh2-docs amzn 2023 | 1.10.0-1.amzn2023.0.5 | [ALAS2023-2026-1966](https://patchblox.com/security/data/fix/linux/alas2023-2026-1966.md) | Jul 20, 2026 |
| Linux | libssh2_org opensuse-leap 16.0 | 1.11.1-160000.5.1 | [OPENSUSE-SU-2026:21549-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21549-1.md) | Aug 10, 2026 |
| Linux | libssh2_org sles 15.6 | 1.11.0-150600.20.6.1 | [SUSE-SU-2026:3541-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3541-1.md) | Aug 10, 2026 |
| Linux | libssh2_org sles 15.7 | 1.11.0-150600.20.6.1 | [SUSE-SU-2026:3541-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3541-1.md) | Aug 10, 2026 |
| Linux | libssh2_org sles 16.0 | 1.11.1-160000.5.1 | [SUSE-SU-2026:23225-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23225-1.md) | Aug 10, 2026 |

---

Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.