---
id: CVE-2023-51384
title: >-
  In ssh-agent in OpenSSH before 9.6, certain destination constraints can be
  incompletely applied
summary: >-
  In ssh-agent in OpenSSH before 9.6, certain destination constraints can be
  incompletely applied. When destination constraints are specified during
  addition of PKCS#11-hosted private keys, these constraints are only applied to
  the first k…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-284
vendor: openbsd
product: openssh
affected:
  - 'openssh >= 8.9, < 9.6'
  - debian_linux = 11.0
  - debian_linux = 12.0
patched:
  - openssh 9.6
published: '2023-12-18'
updated: '2026-07-14'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-51384'
references:
  - url: 'http://seclists.org/fulldisclosure/2024/Mar/21'
    label: cve@mitre.org
  - url: >-
      https://github.com/openssh/openssh-portable/commit/881d9c6af9da4257c69c327c4e2f1508b2fa754b
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20240105-0005/'
    label: cve@mitre.org
  - url: 'https://support.apple.com/kb/HT214084'
    label: cve@mitre.org
  - url: 'https://www.debian.org/security/2023/dsa-5586'
    label: cve@mitre.org
  - url: 'https://www.openssh.com/txt/release-9.6'
    label: cve@mitre.org
  - url: 'https://www.openwall.com/lists/oss-security/2023/12/18/2'
    label: cve@mitre.org
  - url: 'http://seclists.org/fulldisclosure/2024/Mar/21'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/openssh/openssh-portable/commit/881d9c6af9da4257c69c327c4e2f1508b2fa754b
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20240105-0005/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://support.apple.com/kb/HT214084'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2023/dsa-5586'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.openssh.com/txt/release-9.6'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.openwall.com/lists/oss-security/2023/12/18/2'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-769027.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-794697.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00426
epssPercentile: 0.36473
ingestedAt: '2026-07-14T13:36:54.370Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2023-12-18T20:51:36.976615Z'
---

## Overview

In ssh-agent in OpenSSH before 9.6, certain destination constraints can be incompletely applied. When destination constraints are specified during addition of PKCS#11-hosted private keys, these constraints are only applied to the first key, even if a PKCS#11 token returns multiple keys.

## Affected

- `openssh >= 8.9, < 9.6`
- `debian_linux = 11.0`
- `debian_linux = 12.0`

## Remediation

Upgrade past the affected range:

- `openssh 9.6`