How severe is CVE-2023-28531?

CVE-2023-28531 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-28531 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-28531?

CVE-2023-28531 primarily affects Openbsd Openssh. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-28531?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-28531 published?

CVE-2023-28531 was published on 2023-03-17 and last updated on 2026-07-14.

CVE-2023-28531

CVE-2023-28531 is a critical-severity vulnerability in Openbsd Openssh with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-284.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Openbsd Openssh
Published: 2023-03-17
Last modified: 2026-07-14

Description

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

Frequently asked questions

What is CVE-2023-28531?: ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.
How severe is CVE-2023-28531?: CVE-2023-28531 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-28531 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28531?: CVE-2023-28531 primarily affects Openbsd Openssh. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-28531?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-28531 published?: CVE-2023-28531 was published on 2023-03-17 and last updated on 2026-07-14.

References

Affected products (4)

cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:*
cpe:2.3:o:netapp:brocade_fabric_operating_system:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:hci_bootstrap_os:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:solidfire_element_os:-:*:*:*:*:*:*:*

More vulnerabilities in Openbsd Openssh

CVE-2003-0786 — Critical (CVSS 10.0): The SSH1 PAM challenge response authentication in OpenSSH 3.7.1 and 3.7.1p1, when Privilege Separation is disabled,…
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CVE-2002-0640 — Critical (CVSS 10.0): Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large…
CVE-2001-0144 — Critical (CVSS 10.0): CORE SDI SSH1 CRC-32 compensation attack detector allows remote attackers to execute arbitrary commands on an SSH…
CVE-2000-0999 — Critical (CVSS 10.0): Format string vulnerabilities in OpenBSD ssh program (and possibly other BSD-based operating systems) allow attackers…
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All CVEs affecting Openbsd Openssh →

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CVE-2026-66803 — Critical (CVSS 10.0): Improper access control in Azure Cosmos DB allows an unauthorized attacker to execute code over a network.
CVE-2026-58630 — Critical (CVSS 10.0): Improper access control in Azure App Service allows an unauthorized attacker to elevate privileges over a network.
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Browse all CWE-284 (Improper Access Control) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

118.70.178.158 (ipv4-addr)
8.160.182.102 (ipv4-addr)
45.43.60.220 (ipv4-addr)
51.158.248.122 (ipv4-addr)
182.95.111.46 (ipv4-addr)
163.7.9.194 (ipv4-addr)
146.190.220.60 (ipv4-addr)
70.8.241.105 (ipv4-addr)