CVE Intelligence
Critical Access control

CVE-2023-28531 — ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop...

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.

Published Mar 17, 2023 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: mitre

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 2.3% (30-day exploitation probability)+12
  • Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
2.27%
ahead of 83% of scored CVEs · Oct 14, 2026
Affects
Netapp
Brocade Fabric Operating System and 3 more
CVSS base
9.8
Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Netapp Brocade Fabric Operating System, Netapp Hci Bootstrap Os, Netapp Solidfire Element Os…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Netapp Brocade Fabric Operating System versions not specified by the source Vulnerable NIST National Vulnerability Database
Netapp Hci Bootstrap Os versions not specified by the source Vulnerable NIST National Vulnerability Database
Netapp Solidfire Element Os versions not specified by the source Vulnerable NIST National Vulnerability Database
Openbsd Openssh ≥ 8.9 and < 9.3 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
9.8 CVSS 3.1 Critical 3.9 5.9 nvd@nist.gov via NIST National Vulnerability Database
9.8 CVSS 3.1 Critical — — GitHub, Inc. via GitHub Security Advisories
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-284 · Improper Access Control

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Audit administrative actions and access to resources outside each user’s normal pattern.
web/proxy/WAF logsnetwork IDS/IPSauthentication logsapplication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 14, 2026
  • Affected products added · openbsd/openssh, netapp/brocade fabric operating system, netapp/hci bootstrap os, netapp/solidfire element os
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 9.8
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2023
  • CVE published
    Mar 17, 2023 · mitre

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

14 on the record

Elsewhere on this site

Netapp
every CVE for this vendor
Access control
same class
CWE-284
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-106583 In ssh in OpenSSH before 10.6, a $ or \ character can occur in a command-line username, leading... 8d
  • CVE-2026-106587 Type Confusion in Openbsd Openssh 8d
  • CVE-2026-106589 In sshd in OpenSSH through 10.6, in certain environments such as QNX 6 and SCO… 8d
  • CVE-2026-106588 In sshd in OpenSSH through 10.6, use of the macOS 27 (or later) SDK has the side effect… 8d
  • CVE-2026-106555 Incorrect Resource Transfer Between Spheres in Openbsd Openssh 8d
  • CVE-2026-106585 In sshd and ssh in OpenSSH before 10.6, there is no check for whether the maximum packet length... 8d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2023-28531 is "ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop...", rated Critical. It affects Brocade Fabric Operating System (Netapp); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 2.27% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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