Vulnerability-Lookup

FKIE_CVE-2026-107785

Vulnerability from fkie_nvd - Published: 2026-10-09 14:17 - Updated: 2026-10-09 17:16

Severity

6.3 (Medium) - CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:U/S:N/AU:Y/R:A/V:C/RE:L/U:Amber

Summary

Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted. For a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the "Enforce SKA Use" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer's traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel.

References

	URL	Tags
	d0a6edd6-4b7d-45f2-a6f9-9b944f7b6132	https://sirius.computer/security-disclosure-policy/

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Crux Agent",
          "vendor": "Sirius Computer, Inc.",
          "versions": [
            {
              "lessThan": "2.0.3",
              "status": "affected",
              "version": "1.9.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "d0a6edd6-4b7d-45f2-a6f9-9b944f7b6132"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted.\n\n\n\nFor a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the \"Enforce SKA Use\" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer\u0027s traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel."
    }
  ],
  "id": "CVE-2026-107785",
  "lastModified": "2026-10-09T17:16:45.597",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "YES",
          "Recovery": "AUTOMATIC",
          "Safety": "NEGLIGIBLE",
          "attackComplexity": "HIGH",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.3,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "UNREPORTED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "AMBER",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "CONCENTRATED",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:A/V:C/RE:L/U:Amber",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "LOW"
        },
        "source": "d0a6edd6-4b7d-45f2-a6f9-9b944f7b6132",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-107785",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-09T16:15:28.101092Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-09T14:17:19.227",
  "references": [
    {
      "source": "d0a6edd6-4b7d-45f2-a6f9-9b944f7b6132",
      "url": "https://sirius.computer/security-disclosure-policy/"
    }
  ],
  "sourceIdentifier": "d0a6edd6-4b7d-45f2-a6f9-9b944f7b6132",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-252"
        },
        {
          "lang": "en",
          "value": "CWE-325"
        },
        {
          "lang": "en",
          "value": "CWE-394"
        }
      ],
      "source": "d0a6edd6-4b7d-45f2-a6f9-9b944f7b6132",
      "type": "Secondary"
    }
  ]
}

CVE-2026-107785 (GCVE-0-2026-107785)

Vulnerability from cvelistv5 – Published: 2026-10-09 13:15 – Updated: 2026-10-09 16:46

Title

Crux Agent silently fails SKA preshared key rotation when SHA-512 peering is negotiated

Summary

Severity

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:U/S:N/AU:Y/R:A/V:C/RE:L/U:Amber

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-09 16:15 UTC

CWE

CWE-394 - Unexpected Status Code or Return Value
CWE-252 - Unchecked Return Value
CWE-325 - Missing Cryptographic Step

Assigner

sirius CNA under the mitre root

CNA scorecard – unranked: 1 record in the last 180 days, 10 needed details

References

1 reference

URL	Tags
https://sirius.computer/security-disclosure-policy/	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
Sirius Computer, Inc.	Crux Agent	Affected: 1.9.0 , < 2.0.3 (semver)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-107785",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-09T16:15:28.101092Z",
                "version": "2.0.3"
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        "providerMetadata": {
          "dateUpdated": "2026-10-09T16:46:40.880Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Crux Agent",
          "vendor": "Sirius Computer, Inc.",
          "versions": [
            {
              "lessThan": "2.0.3",
              "status": "affected",
              "version": "1.9.0",
              "versionType": "semver"
            }
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        }
      ],
      "descriptions": [
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          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eCrux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted.\u003c/p\u003e\u003cp\u003eFor a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the \"Enforce SKA Use\" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer\u0027s traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel.\u003c/p\u003e"
            }
          ],
          "value": "Crux Agent from 1.9.0 before 2.0.3 uses the full SKA bilocation key as the WireGuard preshared key. When a peering session negotiates use of SHA-512, the key produced is 64 bytes instead of the 32 bytes WireGuard requires. The agent does not validate this size; instead it attempts to use the `wg set` command to update the live tunnel, and write the invalid key to the WireGuard configuration file. The update fails, so the live tunnel keeps using its previous preshared key until the tunnel is shut down. The tunnel will fail to start when restarted.\n\n\n\nFor a peer which has never successfully negotiated a 32-byte bilocation key in a Crux C2 organization which has the \"Enforce SKA Use\" setting turned off, no preshared key will be set for the tunnel. Therefore, an attacker who is able to intercept and store the peer\u0027s traffic, and has access (or will have access) to a cryptographically relevant quantum computer, will be able to decrypt the tunnel."
        }
      ],
      "impacts": [
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          "descriptions": [
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      "metrics": [
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            "Recovery": "AUTOMATIC",
            "Safety": "NEGLIGIBLE",
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "UNREPORTED",
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            "providerUrgency": "AMBER",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
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            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:U/S:N/AU:Y/R:A/V:C/RE:L/U:Amber",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "LOW"
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          "scenarios": [
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              "value": "GENERAL"
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        {
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              "description": "CWE-325: Missing Cryptographic Step",
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              "value": "\u003cp\u003eUpgrade to Crux Agent 2.0.3 or later, which truncates the SKA key to the 32 bytes WireGuard requires. As a workaround, remove any custom settings for \"Hash Function\" in the agent\u0027s configuration (so as to use the default SHA-256 hash function).\u003c/p\u003e"
            }
          ],
          "value": "Upgrade to Crux Agent 2.0.3 or later, which truncates the SKA key to the 32 bytes WireGuard requires. As a workaround, remove any custom settings for \"Hash Function\" in the agent\u0027s configuration (so as to use the default SHA-256 hash function)."
        }
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    "datePublished": "2026-10-09T13:15:57.779Z",
    "dateReserved": "2026-10-08T20:13:33.223Z",
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    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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}

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.
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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.

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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FKIE_CVE-2026-107785

CVE-2026-107785 (GCVE-0-2026-107785)

Tags

Sightings

Nomenclature

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