Description
The (1) SSH_MSG_NEWKEYS and (2) SSH_MSG_KEXDH_REPLY packet handlers in package_cb.c in libssh before 0.6.5 do not properly validate state, which allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a crafted SSH packet.
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 | 0.6.3-4.2 | — |
| Debian 13 | libssh | 0.6.3-4.2 | — |
| Debian 12 | libssh | 0.6.3-4.2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | libssh | 0.6.1-0ubuntu3.3 | USN-2912-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | libssh | 0.6.3-8.1 | SUSE-SU-2015:1707-2, SUSE-SU-2015:1707-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libssh | 0.7.2-2.1 | openSUSE-SU-2024:10036-1 |
Advisories 5
- USN-2912-1 libssh vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2024:10036-1 libssh-devel-0.7.2-2.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1707-2 Security update for libssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1707-1 Security update for libssh SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-1054 libssh: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 7, 2024
References
- USN-2912-1 vendor-advisory
- FEDORA-2015-10962 vendor-advisory
- https://www.libssh.org/security/advisories/CVE-2015-3146.txt
- FEDORA-2015-7590 vendor-advisory
- https://www.libssh.org/2015/04/30/libssh-0-6-5-security-and-bugfix-release/
- DSA-3488 vendor-advisory
- https://git.libssh.org/projects/libssh.git/commit/?h=libssh-0.6.5&id=94f6955fbaee6fda9385a23e505497efe21f5b4f