Vulnerability-Lookup

GHSA-XPR9-GRJF-6FM6

Vulnerability from github – Published: 2026-09-16 21:32 – Updated: 2026-09-16 21:32

Details

A vulnerability in Cisco Secure FMC Software could allow an authenticated, remote attacker to execute arbitrary commands at the root privilege level.

This vulnerability is due to unsecured deserialization of web-management user-controlled data. An attacker could exploit this vulnerability by authenticating to the device and sending a crafted HTTP payload. A successful exploit could allow the attacker to save the crafted payload and then execute it on the underlying operating system as root. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (read-only).

Severity

8.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-20340"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T21:17:11Z",
    "severity": "HIGH"
  },
  "details": "A vulnerability in Cisco Secure FMC Software could allow an authenticated, remote attacker to execute arbitrary commands at the\u0026nbsp;root privilege level.\n\nThis vulnerability is due to unsecured deserialization of web-management user-controlled data. An attacker could exploit this vulnerability by authenticating to the device and sending a crafted HTTP payload. A successful exploit could allow the attacker to save the crafted payload and then execute it on the underlying operating system as root.\nTo exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (read-only).",
  "id": "GHSA-xpr9-grjf-6fm6",
  "modified": "2026-09-16T21:32:50Z",
  "published": "2026-09-16T21:32:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20340"
    },
    {
      "type": "WEB",
      "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-20340 (GCVE-0-2026-20340)

Vulnerability from cvelistv5 – Published: 2026-09-16 20:10 – Updated: 2026-09-17 16:02

Title

Cisco Secure Firewall Management Center Software Deserialization Arbitrary Root Command Execution Vulnerability

Summary

A vulnerability in Cisco Secure FMC Software could allow an authenticated, remote attacker to execute arbitrary commands at the root privilege level. This vulnerability is due to unsecured deserialization of web-management user-controlled data. An attacker could exploit this vulnerability by authenticating to the device and sending a crafted HTTP payload. A successful exploit could allow the attacker to save the crafted payload and then execute it on the underlying operating system as root. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (read-only).

Severity

8.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-17 16:02 UTC

CWE

CWE-502 - Deserialization of Untrusted Data

Assigner

cisco mitre root

References

1 reference

URL	Tags
https://sec.cloudapps.cisco.com/security/center/c…

Impacted products

1 product

Vendor	Product	Version
Cisco	Cisco Secure Firewall Management Center (FMC)	Affected: 7.0.0 Affected: 7.0.0.1 Affected: 7.0.1 Affected: 7.0.1.1 Affected: 7.0.2 Affected: 7.2.0 Affected: 7.0.2.1 Affected: 7.0.3 Affected: 7.2.0.1 Affected: 7.0.4 Affected: 7.2.1 Affected: 7.0.5 Affected: 7.3.0 Affected: 7.2.2 Affected: 7.3.1 Affected: 7.2.3 Affected: 7.2.3.1 Affected: 7.2.4 Affected: 7.0.6 Affected: 7.2.4.1 Affected: 7.2.5 Affected: 7.3.1.1 Affected: 7.4.0 Affected: 7.0.6.1 Affected: 7.2.5.1 Affected: 7.4.1 Affected: 7.2.6 Affected: 7.4.1.1 Affected: 7.0.6.2 Affected: 7.2.7 Affected: 7.2.5.2 Affected: 7.3.1.2 Affected: 7.2.8 Affected: 7.6.0 Affected: 7.4.2 Affected: 7.2.8.1 Affected: 7.0.6.3 Affected: 7.4.2.1 Affected: 7.2.9 Affected: 7.0.7 Affected: 7.7.0 Affected: 7.4.2.2 Affected: 7.2.10 Affected: 7.6.1 Affected: 7.4.2.3 Affected: 7.0.8 Affected: 7.6.2 Affected: 7.7.10 Affected: 7.2.10.1 Affected: 7.0.8.1 Affected: 7.6.2.1 Affected: 7.2.10.2 Affected: 7.7.10.1 Affected: 7.4.2.4 Affected: 7.4.3 Affected: 7.6.3 Affected: 7.7.11 Affected: 7.6.4 Affected: 10.0.0 Affected: 7.4.4 Affected: 7.4.5 Affected: 7.0.9 Affected: 7.2.11 Affected: 7.7.12 Affected: 7.6.5 Affected: 7.4.6 Affected: 10.0.1 Affected: 7.4.7

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-20340",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-17T16:02:18.636037Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-17T16:02:28.295Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "product": "Cisco Secure Firewall Management Center (FMC)",
          "vendor": "Cisco",
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              "status": "affected",
              "version": "7.0.0"
            },
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              "status": "affected",
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            {
              "status": "affected",
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              "status": "affected",
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            {
              "status": "affected",
              "version": "7.0.2"
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            {
              "status": "affected",
              "version": "7.2.0"
            },
            {
              "status": "affected",
              "version": "7.0.2.1"
            },
            {
              "status": "affected",
              "version": "7.0.3"
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            {
              "status": "affected",
              "version": "7.2.0.1"
            },
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              "status": "affected",
              "version": "7.0.4"
            },
            {
              "status": "affected",
              "version": "7.2.1"
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              "status": "affected",
              "version": "7.0.5"
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            {
              "status": "affected",
              "version": "7.3.0"
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              "status": "affected",
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              "status": "affected",
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            {
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              "version": "7.2.5"
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            {
              "status": "affected",
              "version": "7.3.1.1"
            },
            {
              "status": "affected",
              "version": "7.4.0"
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            {
              "status": "affected",
              "version": "7.0.6.1"
            },
            {
              "status": "affected",
              "version": "7.2.5.1"
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            {
              "status": "affected",
              "version": "7.4.1"
            },
            {
              "status": "affected",
              "version": "7.2.6"
            },
            {
              "status": "affected",
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              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "7.2.7"
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            {
              "status": "affected",
              "version": "7.2.5.2"
            },
            {
              "status": "affected",
              "version": "7.3.1.2"
            },
            {
              "status": "affected",
              "version": "7.2.8"
            },
            {
              "status": "affected",
              "version": "7.6.0"
            },
            {
              "status": "affected",
              "version": "7.4.2"
            },
            {
              "status": "affected",
              "version": "7.2.8.1"
            },
            {
              "status": "affected",
              "version": "7.0.6.3"
            },
            {
              "status": "affected",
              "version": "7.4.2.1"
            },
            {
              "status": "affected",
              "version": "7.2.9"
            },
            {
              "status": "affected",
              "version": "7.0.7"
            },
            {
              "status": "affected",
              "version": "7.7.0"
            },
            {
              "status": "affected",
              "version": "7.4.2.2"
            },
            {
              "status": "affected",
              "version": "7.2.10"
            },
            {
              "status": "affected",
              "version": "7.6.1"
            },
            {
              "status": "affected",
              "version": "7.4.2.3"
            },
            {
              "status": "affected",
              "version": "7.0.8"
            },
            {
              "status": "affected",
              "version": "7.6.2"
            },
            {
              "status": "affected",
              "version": "7.7.10"
            },
            {
              "status": "affected",
              "version": "7.2.10.1"
            },
            {
              "status": "affected",
              "version": "7.0.8.1"
            },
            {
              "status": "affected",
              "version": "7.6.2.1"
            },
            {
              "status": "affected",
              "version": "7.2.10.2"
            },
            {
              "status": "affected",
              "version": "7.7.10.1"
            },
            {
              "status": "affected",
              "version": "7.4.2.4"
            },
            {
              "status": "affected",
              "version": "7.4.3"
            },
            {
              "status": "affected",
              "version": "7.6.3"
            },
            {
              "status": "affected",
              "version": "7.7.11"
            },
            {
              "status": "affected",
              "version": "7.6.4"
            },
            {
              "status": "affected",
              "version": "10.0.0"
            },
            {
              "status": "affected",
              "version": "7.4.4"
            },
            {
              "status": "affected",
              "version": "7.4.5"
            },
            {
              "status": "affected",
              "version": "7.0.9"
            },
            {
              "status": "affected",
              "version": "7.2.11"
            },
            {
              "status": "affected",
              "version": "7.7.12"
            },
            {
              "status": "affected",
              "version": "7.6.5"
            },
            {
              "status": "affected",
              "version": "7.4.6"
            },
            {
              "status": "affected",
              "version": "10.0.1"
            },
            {
              "status": "affected",
              "version": "7.4.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A vulnerability in Cisco Secure FMC Software could allow an authenticated, remote attacker to execute arbitrary commands at the\u0026nbsp;root privilege level.\r\n\r\nThis vulnerability is due to unsecured deserialization of web-management user-controlled data. An attacker could exploit this vulnerability by authenticating to the device and sending a crafted HTTP payload. A successful exploit could allow the attacker to save the crafted payload and then execute it on the underlying operating system as root.\r\nTo exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (read-only)."
        }
      ],
      "exploits": [
        {
          "lang": "en",
          "value": "The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "cvssV3_1"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-502",
              "description": "Deserialization of Untrusted Data",
              "lang": "en",
              "type": "cwe"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T20:10:07.218Z",
        "orgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
        "shortName": "cisco"
      },
      "references": [
        {
          "name": "cisco-sa-fmc-mulivulns-4PsnFwvx",
          "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx"
        }
      ],
      "source": {
        "advisory": "cisco-sa-fmc-mulivulns-4PsnFwvx",
        "defects": [
          "CSCwu27275"
        ],
        "discovery": "INTERNAL"
      },
      "title": "Cisco Secure Firewall Management Center Software Deserialization Arbitrary Root Command Execution Vulnerability"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
    "assignerShortName": "cisco",
    "cveId": "CVE-2026-20340",
    "datePublished": "2026-09-16T20:10:07.218Z",
    "dateReserved": "2025-10-08T11:59:15.413Z",
    "dateUpdated": "2026-09-17T16:02:28.295Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
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.

Detection rules are retrieved from Rulezet.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.