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On CISA KEVHigh

CVE-2026-123158OpenSSH Vulnerability

sshd in OpenSSH before 10.6p2 on Linux, when musl libc is used without PAM, lacks a workaround for a password authentication bypass (related to misinterpretation of whether a string is intended to be a password hash).

Published Nov 5, 2026 · Updated Nov 6, 2026 · Also known as EUVD-2026-117552, GHSA-4fcc-vm97-gx3x

Key Facts

Patch immediately
  • CVE-2026-123158 is a high-severity vulnerability (CVSS 8.1 v3.1) affecting OpenSSH (Openbsd).
  • It is exploited in the wild, listed in Industry KEV feed since Nov 6, 2026. A public exploit is reported by tracking sources, but no code link is listed yet.
  • EPSS estimates a 1.0% probability of exploitation in the next 30 days.
  • Fixed versions are available, including OpenSSH 10.6p2.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

Scores

CVSS v3.1

8.1

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS (30-day exploit likelihood)

1.0%

Higher than 62.2% of all scored CVEs

Exploit maturity

Exploited (KEV)

ATLAS score

70/100

Publication score, see How it works

Exploitation Verdict

KEV listed

Nov 6, 2026

1 days after publication

Federal due date

None

No federal due date

Ransomware use

Not reported

Attributed actors

None named

Exploit & Defence Guidance

Exploit maturity

Exploited (KEV)

Public exploit code

10

Proof-of-concept links

In-the-wild evidence

2

Reports of active use

Description

sshd in OpenSSH before 10.6p2 on Linux, when musl libc is used without PAM, lacks a workaround for a password authentication bypass (related to misinterpretation of whether a string is intended to be a password hash). For some configurations of accounts, any password between 256 and 1024 characters succeeds. An example of a platform using musl libc without PAM is Alpine Linux.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
Industry KEV feedNov 6, 2026n/aNot reported

Affected Products

3 affected entries in total
ProductAffected versionsFixed in
OpenSSHOpenbsdSee advisory10.6p2

Patched Releases

OpenSSH

10.6p2

Timeline

  1. Publicly disclosed

    Nov 5, 2026

  2. Added to Industry KEV feed

    Nov 6, 2026

  3. Last updated

    Nov 6, 2026

Weakness Type

  • CWE-303 Incorrect Implementation of Authentication Algorithm
  • CWE-394 Unexpected Status Code or Return Value

FAQ

Common Questions.

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More vulnerabilities

Figures as of Nov 6, 2026. Compiled by Brandefense technologies from public vulnerability catalogs; scoring as described in How it works.

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