CVE-2026-35414Network attack vector

Unintended account access via comma-confused principal matching

Published Apr 2, 2026 · Updated Apr 2, 2026

Authentication bypass in OpenSSH before 10.3 allows remote authenticated users to access unintended accounts with a CA-signed certificate. The sshd match_principals_option path treats a comma-bearing certificate principal as comma-delimited input instead of requiring an exact principal-name match. Reachability requires a user-trusted CA entry with multiple names in its principals option and a CA that issues the crafted principal; TrustedUserCAKeys is unaffected.

CVSS severity4.2
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in OpenSSH before 10.3 allows remote authenticated users to access unintended accounts with a CA-signed certificate. The sshd match_principals_option path treats a comma-bearing certificate principal as comma-delimited input instead of requiring an exact principal-name match. Reachability requires a user-trusted CA entry with multiple names in its principals option and a CA that issues the crafted principal; TrustedUserCAKeys is unaffected.

The record

CVE
CVE-2026-35414
Published
Apr 2, 2026
Updated
Apr 2, 2026
Vendor
OpenBSD Project
Product
OpenSSH
Classifications
CWE-670, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <10.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenBSD Project · OpenSSHversion=0 <10.3

Published CVSS scores

4.2MITRECVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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