Description
sshd in OpenSSH before 7.4 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an out-of-sequence NEWKEYS message, as demonstrated by Honggfuzz, related to kex.c and packet.c.
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 | openssh | 1:7.4p1-1 | — |
| Debian 13 | openssh | 1:7.4p1-1 | — |
| Debian 12 | openssh | 1:7.4p1-1 | — |
| Debian 8 | openssh | 1:6.7p1-5+deb8u6 | DLA-1500-1 |
| Debian 7 | openssh | 1:6.0p1-4+deb7u7 | DLA-1257-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | openssh | 1:7.6p1-4ubuntu0.1 | USN-3809-1 |
| Ubuntu 16.04 LTS | openssh | 1:7.2p2-4ubuntu2.6 | USN-3809-1 |
| Ubuntu 14.04 LTS | openssh | 1:6.6p1-2ubuntu2.11 | USN-3809-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | openssh +7 | 7.4p1-11.el7 | RHSA-2017:2029 |
| RHEL 7 | pam_ssh_agent_auth | 0.10.3-1.11.el7 | RHSA-2017:2029 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | openssh +1 | 7.2p2-74.19.1 | SUSE-SU-2018:1989-1 |
| SLES 12 SP2 | openssh +1 | 7.2p2-74.25.1 | SUSE-SU-2018:2530-2, SUSE-SU-2018:2530-1 |
| SLES 12 SP1 | openssh | 6.6p1-54.15.2 | SUSE-SU-2018:2685-1 |
| SLES 12 SP1 | openssh-askpass-gnome | 6.6p1-54.15.1 | SUSE-SU-2018:2685-1 |
| SLES 12 | openssh | 6.6p1-54.15.2 | SUSE-SU-2018:2685-1 |
| SLES 12 | openssh-askpass-gnome | 6.6p1-54.15.1 | SUSE-SU-2018:2685-1 |
| SLES 11 SP4 | openssh +1 | 6.6p1-36.3.1 | SUSE-SU-2018:2275-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP3 | openssh +1 | 6.2p2-0.41.5.1 | SUSE-SU-2018:3540-1 |
| SLES 11 | openssh-openssl1 | 6.6p1-19.3.1 | SUSE-SU-2018:2719-1 |
| SLES for SAP 12 SP3 | openssh +1 | 7.2p2-74.19.1 | SUSE-SU-2018:1989-1 |
| SLES for SAP 12 SP2 | openssh +1 | 7.2p2-74.25.1 | SUSE-SU-2018:2530-1 |
| SLES for SAP 12 SP1 | openssh | 6.6p1-54.15.2 | SUSE-SU-2018:2685-1 |
| SLES for SAP 12 SP1 | openssh-askpass-gnome | 6.6p1-54.15.1 | SUSE-SU-2018:2685-1 |
| SLES for SAP 11 SP4 | openssh +1 | 6.6p1-36.3.1 | SUSE-SU-2018:2275-1 |
| SUSE OpenStack Cloud 7 | openssh +1 | 7.2p2-74.25.1 | SUSE-SU-2018:2530-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | openssh +1 | 6.2p2-0.41.5.1 | SUSE-SU-2018:3540-1 |
| SUSE Enterprise Storage 4 | openssh +1 | 7.2p2-74.25.1 | SUSE-SU-2018:2530-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
lggcs/CVE-2016-10708 ★ 1 · Sep 29, 2025
This proof-of-concept script exploits a vulnerability in OpenSSH versions prior to 7.4 (CVE-2016-10708) by sending unexpected `SSH_MSG_NEWKEYS` packets.
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 12
- RHSA-2017:2029 Red Hat Security Advisory: openssh security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3809-1 openssh vulnerabilities Ubuntu Security Notices (USN) · May 4, 2026
- DLA-1257-1 openssh - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1500-1 openssh - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:2530-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2530-2 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2719-1 Security update for openssh-openssl1 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:1989-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2275-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:3540-1 Security update for openssh SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:2685-1 Security update for openssh SUSE / openSUSE Security Updates · May 2, 2025
- SSA-676336 SSA-676336: OpenSSH Vulnerabilities in SCALANCE X-200 and X-300/X408 Switches Siemens ProductCERT · Apr 11, 2023
References
- https://www.openssh.com/releasenotes.html
- https://security.netapp.com/advisory/ntap-20180423-0003/
- [debian-lts-announce] 20180126 [SECURITY] [DLA 1257-1] openssh security update mailing-list
- https://anongit.mindrot.org/openssh.git/commit/?id=28652bca29046f62c7045e933e6b931de1d16737
- USN-3809-1 vendor-advisory
- 102780 vdb-entry
- [debian-lts-announce] 20180910 [SECURITY] [DLA 1500-1] openssh security update mailing-list
- http://blog.swiecki.net/2018/01/fuzzing-tcp-servers.html
- https://kc.mcafee.com/corporate/index?page=content&id=SB10284
- https://support.f5.com/csp/article/K32485746?utm_source=f5support&%3Butm_medium=RSS
- https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf