Vulnerability-Lookup

GHSA-XX8J-QHMG-CJ8F

Vulnerability from github – Published: 2026-10-22 00:31 – Updated: 2026-10-22 03:33

Details

Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no.

Every remote branch of sync builds its ssh command with that option, for password authentication, for private-key authentication and for the fallback. The ssh options a caller sets through set_openssh_opt reach the OpenSSH transport but not this command, so there is no configuration that restores host key checking for the transfer.

An attacker who can redirect the connection before the real host key is known presents their own and the transfer proceeds: under password authentication sync sends the connection password to that server, an upload writes the selected local files to it, and a download writes what it returns to the local destination.

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-94140"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-322"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-21T22:16:50Z",
    "severity": null
  },
  "details": "Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no.\n\nEvery remote branch of sync builds its ssh command with that option, for password authentication, for private-key authentication and for the fallback. The ssh options a caller sets through set_openssh_opt reach the OpenSSH transport but not this command, so there is no configuration that restores host key checking for the transfer.\n\nAn attacker who can redirect the connection before the real host key is known presents their own and the transfer proceeds: under password authentication sync sends the connection password to that server, an upload writes the selected local files to it, and a download writes what it returns to the local destination.",
  "id": "GHSA-xx8j-qhmg-cj8f",
  "modified": "2026-10-22T03:33:32Z",
  "published": "2026-10-22T00:31:59Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94140"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/FERKI/Rex-1.16.1/source/lib/Rex/Commands/Rsync.pm"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/10/21/28"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-94140 (GCVE-0-2026-94140)

Vulnerability from cvelistv5 – Published: 2026-10-21 21:22 – Updated: 2026-10-22 00:16

Title

Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no

Summary

Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no. Every remote branch of sync builds its ssh command with that option, for password authentication, for private-key authentication and for the fallback. The ssh options a caller sets through set_openssh_opt reach the OpenSSH transport but not this command, so there is no configuration that restores host key checking for the transfer. An attacker who can redirect the connection before the real host key is known presents their own and the transfer proceeds: under password authentication sync sends the connection password to that server, an upload writes the selected local files to it, and a download writes what it returns to the local destination.

Severity

No CVSS data available.

CWE

CWE-322 - Key Exchange without Entity Authentication

Assigner

CPANSec CNA under the redhat root

CNA scorecard C 63/100 over 296 records in the last 180 days details

References

2 references

URL	Tags
https://metacpan.org/release/FERKI/Rex-1.16.1/sou…	technical-description
http://www.openwall.com/lists/oss-security/2026/1…

Impacted products

1 product

Vendor	Product	Version
		Affected: 0 , ≤ 1.16.1 (custom)

Credits

James Klein

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-10-22T00:16:43.835Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/10/21/28"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Rex"
          ],
          "packageName": "Rex",
          "packageURL": "pkg:cpan/Rex",
          "programFiles": [
            "lib/Rex/Commands/Rsync.pm"
          ],
          "programRoutines": [
            {
              "name": "Rex::Commands::Rsync::sync"
            }
          ],
          "repo": "https://github.com/RexOps/Rex",
          "versions": [
            {
              "lessThanOrEqual": "1.16.1",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "James Klein"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no.\n\nEvery remote branch of sync builds its ssh command with that option, for password authentication, for private-key authentication and for the fallback. The ssh options a caller sets through set_openssh_opt reach the OpenSSH transport but not this command, so there is no configuration that restores host key checking for the transfer.\n\nAn attacker who can redirect the connection before the real host key is known presents their own and the transfer proceeds: under password authentication sync sends the connection password to that server, an upload writes the selected local files to it, and a download writes what it returns to the local destination."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-322",
              "description": "CWE-322 Key Exchange without Entity Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T21:22:19.577Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://metacpan.org/release/FERKI/Rex-1.16.1/source/lib/Rex/Commands/Rsync.pm"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "No fixed CPAN release is currently available."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-94140",
    "datePublished": "2026-10-21T21:22:19.577Z",
    "dateReserved": "2026-09-20T19:46:50.250Z",
    "dateUpdated": "2026-10-22T00:16:43.835Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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