Description
A flaw was found in the key export functionality of libssh. The issue occurs in the internal function responsible for converting cryptographic keys into serialized formats. During error handling, a memory structure is freed but not cleared, leading to a potential double free issue if an additional failure occurs later in the function. This condition may result in heap corruption or application instability in low-memory scenarios, posing a risk to system reliability where key export operations are performed.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| libssh | libssh | 0.10.0 – < 0.11.2 | 0.11.2 |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 6 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libssh | 0.11.2-1 | — |
| Debian 13 | libssh | 0.11.2-1 | — |
| Debian 12 | libssh | 0.10.6-0+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | libssh | 0.10.6-2ubuntu0.1 | USN-7619-1 |
| Ubuntu 22.04 LTS | libssh | 0.9.6-2ubuntu0.22.04.4 | USN-7619-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | libssh +2 | 0.10.4-18.el9 | RHSA-2026:18683 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | libssh +2 | 0.10.4-18.el9 | ALSA-2026:18683 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 9 | libssh | 0.10.4-18.el9 | RLSA-2026:18683 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | libssh | 0.10.6-slfo.1.1_2.1 | SUSE-SU-2025:20596-1 |
| SLE Micro 6.0 | libssh | 0.10.6-2.1 | SUSE-SU-2025:20557-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libssh | 0.11.2-1.1 | openSUSE-SU-2025:15243-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libssh | 0.11.2-r0 | — |
| Alpine v3.23 | libssh | 0.11.2-r0 | — |
| Alpine v3.22 | libssh | 0.11.2-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | libssh +2 | 0.10.6-1.amzn2023.0.2 | ALAS2023-2025-1155 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libssh | 0.10.6-2 | — |
| Azure Linux 2 (CBL-Mariner) | libssh | 0.10.6-2 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | libssh +2 | 0.10.4-18.el9 | ELSA-2026-18683 |
Advisories 10
- ALSA-2026:18683 Moderate: libssh security update AlmaLinux Security Advisories · Oct 29, 2026
- USN-7619-1 libssh vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- RHSA-2026:18683 Red Hat Security Advisory: libssh security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- WID-SEC-2025-1423 libssh: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 13, 2026
- ELSA-2026-18683 Moderate: libssh security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 12, 2026
- RLSA-2026:18683 Moderate: libssh security update Rocky Linux Security Advisories · May 28, 2026
- openSUSE-SU-2025:15243-1 libssh-config-0.11.2-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20596-1 Security update for libssh SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20557-1 Security update for libssh SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2023-2025-1155 Moderate: libssh security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 8, 2025
References
- RHSA-2026:18683 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2025-5351 vdb-entry
- RHBZ#2369367 issue-tracking