CVE-2026-44467

SSH session interception via unchecked host key

Published May 13, 2026 · Updated May 13, 2026

Authentication bypass in Anthropic Claude Code allows man-in-the-middle attackers to read and alter SSH remote development traffic. In affected releases starting with 1.2581.0, the SSH feature checks only for the hostname in known_hosts and accepts any presented key instead of comparing it with the stored key. Exploitation requires interception of SSH traffic, a target-host entry in known_hosts, and a version before 1.4304.0.

CVSS severity7.4
High
EPSS probability0.14%
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 Anthropic Claude Code allows man-in-the-middle attackers to read and alter SSH remote development traffic. In affected releases starting with 1.2581.0, the SSH feature checks only for the hostname in known_hosts and accepts any presented key instead of comparing it with the stored key. Exploitation requires interception of SSH traffic, a target-host entry in known_hosts, and a version before 1.4304.0.

The record

CVE
CVE-2026-44467
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Anthropic
Product
Claude Code
Classifications
CWE-297, CWE-322, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 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=>= 1.2581.0, < 1.4304.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Anthropic · Claude Codeversion=>= 1.2581.0, < 1.4304.0

Published CVSS scores

7.4GitHub, Inc.CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
6.8NIST NVDCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-297Improper Validation of Certificate with Host Mismatch
CWE-322Key Exchange without Entity Authentication
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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