Cyber Resilience

CVE-2026-59995

Path Traversal in Openbsd Openssh ≤ 10.4

Published
08 July 2026
Modified
09 July 2026
CVSS Score v3.1 4.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L
EPSS Score 0.0025 17th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-59995 is a medium-severity Relative Path Traversal (CWE-23) vulnerability in Openbsd Openssh. Its CVSS base score is 4.2 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Ingress Tool Transfer (T1105); ranked at the 17th 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 AC-6 (Least Privilege) and CM-7 (Least Functionality) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

sftp in OpenSSH before 10.4 does not properly constrain the location of downloaded files when "sftp server:/path ." is used with an attacker-controlled server.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1105 Ingress Tool Transfer Command And Control
Adversaries may transfer tools or other files from an external system into a compromised environment.
Why these techniques?

The vulnerability allows an attacker-controlled SFTP server to write files to arbitrary locations on the client system when using 'sftp server:/path .', enabling ingress tool transfer (T1105) by placing malicious files outside the intended directory.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-59996Same product: Openbsd Openssh
CVE-2026-35385Same product: Openbsd Openssh
CVE-2026-60000Same product: Openbsd Openssh
CVE-2026-35387Same product: Openbsd Openssh
CVE-2026-35386Same product: Openbsd Openssh
CVE-2026-60001Same product: Openbsd Openssh
CVE-2026-59997Same product: Openbsd Openssh
CVE-2026-60002Same product: Openbsd Openssh
CVE-2026-35414Same product: Openbsd Openssh
CVE-2026-59998Same product: Openbsd Openssh

Affected Assets

openbsd
openssh
≤ 10.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-6 Least Privilege
  • CM-7 Least Functionality
Detect
Catch it (NIST detect / respond)
  • SI-7 Software, Firmware, and Information Integrity
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Least privilege limits the directories and files the sftp client process can write to, directly mitigating the path traversal that allows an attacker-controlled server to place files outside the intended destination.

detect

Software, firmware, and information integrity monitoring can detect unexpected file writes or changes resulting from the uncontrolled sftp download.

prevent

Least functionality can disable or restrict the sftp client subsystem when connecting to untrusted servers, reducing the attack surface for this path-traversal flaw.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and path sanitization that prevent relative traversal.

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.

detects

Security testing in development catches path traversal via static/dynamic analysis, but does not itself implement the fix.

prevents

Secure development lifecycle mandates input validation and path-handling controls that directly prevent relative path traversal.

prevents

Application security requirements explicitly call for controls against path traversal and other injection flaws.

prevents

Secure architecture principles include directory isolation and canonicalization, reducing but not eliminating traversal risk.

prevents

Secure coding standards require neutralizing path traversal sequences, directly addressing CWE-23.

mitigates

Information access restriction limits which files can be reached, mitigating impact but not preventing the traversal flaw.

References