Description
A flaw was found in the SFTP server message decoding logic of libssh. The issue occurs due to an incorrect packet length check that allows an integer overflow when handling large payload sizes on 32-bit systems. This issue leads to failed memory allocation and causes the server process to crash, resulting in a denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | libssh | 0.11.0 – ≤ 0.11.1 | — |
| 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 Enterprise Linux 9 | — | — |
| 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 | — |
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 |
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 | — |
Advisories 3
- USN-7619-1 libssh vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- WID-SEC-2025-1423 libssh: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 13, 2026
- openSUSE-SU-2025:15243-1 libssh-config-0.11.2-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
References
- https://access.redhat.com/security/cve/CVE-2025-5449 vdb-entry
- RHBZ#2369705 issue-tracking
- https://git.libssh.org/projects/libssh.git/commit/?h=stable-0.11&id=261612179f740bc62ba363d98b3bd5e5573a811f
- https://git.libssh.org/projects/libssh.git/commit/?h=stable-0.11&id=3443aec90188d6aab9282afc80a81df5ab72c4da
- https://git.libssh.org/projects/libssh.git/commit/?h=stable-0.11&id=5504ff40515439a5fecbb17da7483000c4d12eb7
- https://git.libssh.org/projects/libssh.git/commit/?h=stable-0.11&id=78485f446af9b30e37eb8f177b81940710d54496
- https://git.libssh.org/projects/libssh.git/commit/?h=stable-0.11&id=f79ec51b7fd519dbc5737a7ba826e3ed093f6ceb
- https://www.libssh.org/security/advisories/CVE-2025-5449.txt