OpenSSH · Sshd
Affects opensshSource GCVE Database
Not known to be exploited · CVSS 4.8 Medium · fixed in 1:6.6p1-2ubuntu2.13+esm4 : update openssh when convenient.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1:6.6p1-2ubuntu2.13+esm4, 1:7.2p2-4ubuntu2.10+esm10, 1:7.6p1-4ubuntu0.7+esm6 +6
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10openssh-ssh1pkg:deb/ubuntu/openssh-ssh1?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSopensshpkg:deb/ubuntu/openssh?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSopenssh-ssh1pkg:deb/ubuntu/openssh-ssh1?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10opensshpkg:deb/ubuntu/openssh?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10openssh-ssh1pkg:deb/ubuntu/openssh-ssh1?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSopensshpkg:deb/ubuntu/openssh?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available and can be applied by updating OpenSSH to versions 10.4 or later. Ubuntu users should apply the security updates provided in Ubuntu security notices USN-8533-1 and USN-8804-1, which include patched OpenSSH packages. Standard system updates will address this issue.
Description
OpenSSH versions prior to 10.4 exhibit an undocumented security-relevant behavior where the GSSAPIStrictAcceptorCheck option has no effect when the server is integrated with Windows Active Directory. This behavior was clarified in updated documentation. The vulnerability has a CVSS score of 6.5 (medium severity) and affects multiple Ubuntu package versions. A fix is available through standard system updates.
References
- ubuntu.com/security/CVE-2026-59998 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-59998 (opens in a new tab)
- openssh.org/releasenotes.html (opens in a new tab)
- ubuntu.com/security/notices/USN-8533-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8804-1 (opens in a new tab)
- marc.info (opens in a new tab)
- openwall.com/lists/oss-security/2026/07/06/5 (opens in a new tab)