CVE-2026-35386
Openbsd Openssh 10.0 – 10.3
Raw vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:NSummary
CVE-2026-35386 is a low-severity Incorrect Behavior Order (CWE-696) vulnerability in Openbsd Openssh. Its CVSS base score is 3.6 (Low).
Operationally, ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and RA-5 (Vulnerability Monitoring and Scanning) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-35386 affects OpenSSH versions prior to 10.3 and involves a vulnerability where command execution can occur via shell metacharacters embedded in a username passed on the command line. This issue arises in scenarios where the username is untrusted and requires a non-default configuration involving the % directive in ssh_config. Classified under CWE-696 (Incorrect Behavior Order: Ascending or Descending), it carries a CVSS v3.1 base score of 3.6 (AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N), indicating low severity with limited impact on confidentiality and integrity but no availability disruption.
Exploitation requires local access (AV:L) by an attacker with low privileges (PR:L), along with high attack complexity (AC:H) due to the specific prerequisites: an untrusted username on the ssh command line and the rare non-default % configuration in ssh_config. A successful attack allows the attacker to execute arbitrary commands through shell metacharacters in the username, potentially leading to limited unauthorized access or modification (low C/I impact), though the unchanged scope (S:U) confines effects to the local system.
OpenSSH release notes for version 10.3p1 document the fix for this issue, recommending an upgrade to mitigate the vulnerability. Announcements on mailing lists such as openssh-unix-dev and oss-security confirm the patch availability and detail the configuration-dependent nature of the flaw.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18400
Vulnerability Data
In OpenSSH before 10.3, command execution can occur via shell metacharacters in a username within a command line. This requires a scenario where the username on the command line is untrusted, and also requires a non-default configurations of % in…
more
ssh_config.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation at post-design stages can discover incorrect ordering of related behaviors before deployment.
Vulnerability scanning may surface order-related weaknesses after code is built but does not address their root cause.
Mandating a documented development process and standards enforces review of behavior ordering within the software lifecycle.
Security and privacy engineering principles applied during design and implementation directly require correct sequencing of operations to avoid introducing order-dependent flaws.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly enforce correct sequencing of security-relevant operations during design and coding.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect ordering flaws but does not prevent them during development.
Secure development life cycle mandates correct sequencing of security activities, directly preventing incorrect behavior order.
Secure system architecture and engineering principles require proper ordering of design and implementation steps.
Secure coding standards enforce correct execution order of security-critical operations.
Change management may catch order-related issues during reviews but does not address root cause.