Vulnerability-Lookup

FKIE_CVE-2026-31976

Vulnerability from fkie_nvd - Published: 2026-03-11 20:16 - Updated: 2026-03-16 19:02

Severity ?

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

xygeni-action is the GitHub Action for Xygeni Scanner. On March 3, 2026, an attacker with access to compromised credentials created a series of pull requests (#46, #47, #48) injecting obfuscated shell code into action.yml. The PRs were blocked by branch protection rules and never merged into the main branch. However, the attacker used the compromised GitHub App credentials to move the mutable v5 tag to point at the malicious commit (4bf1d4e19ad81a3e8d4063755ae0f482dd3baf12) from one of the unmerged PRs. This commit remained in the repository's git object store, and any workflow referencing @v5 would fetch and execute it. This is a supply chain compromise via tag poisoning. Any GitHub Actions workflow referencing xygeni/xygeni-action@v5 during the affected window (approximately March 3–10, 2026) executed a C2 implant that granted the attacker arbitrary command execution on the CI runner for up to 180 seconds per workflow run.

References

	URL	Tags
	security-advisories@github.com	https://github.com/xygeni/xygeni-action/issues/54	Issue Tracking
	security-advisories@github.com	https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh	Vendor Advisory, Patch

Impacted products

	Vendor	Product	Version
	xygeni	xygeni-action	*

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:xygeni:xygeni-action:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "432E19E2-DDB5-4EBB-A540-A07106448E76",
              "versionEndIncluding": "6.4.0",
              "versionStartIncluding": "5.38.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "xygeni-action is the GitHub Action for Xygeni Scanner. On March 3, 2026, an attacker with access to compromised credentials created a series of pull requests (#46, #47, #48) injecting obfuscated shell code into action.yml. The PRs were blocked by branch protection rules and never merged into the main branch. However, the attacker used the compromised GitHub App credentials to move the mutable v5 tag to point at the malicious commit (4bf1d4e19ad81a3e8d4063755ae0f482dd3baf12) from one of the unmerged PRs. This commit remained in the repository\u0027s git object store, and any workflow referencing @v5 would fetch and execute it. This is a supply chain compromise via tag poisoning. Any GitHub Actions workflow referencing xygeni/xygeni-action@v5 during the affected window (approximately March 3\u201310, 2026) executed a C2 implant that granted the attacker arbitrary command execution on the CI runner for up to 180 seconds per workflow run."
    },
    {
      "lang": "es",
      "value": "xygeni-action es la Acci\u00f3n de GitHub para Xygeni Scanner. El 3 de marzo de 2026, un atacante con acceso a credenciales comprometidas cre\u00f3 una serie de solicitudes de extracci\u00f3n (#46, #47, #48) inyectando c\u00f3digo shell ofuscado en action.yml. Las solicitudes de extracci\u00f3n fueron bloqueadas por las reglas de protecci\u00f3n de rama y nunca se fusionaron en la rama principal. Sin embargo, el atacante utiliz\u00f3 las credenciales comprometidas de la aplicaci\u00f3n de GitHub para mover la etiqueta mutable v5 para que apuntara al commit malicioso (4bf1d4e19ad81a3e8d4063755ae0f482dd3baf12) de una de las solicitudes de extracci\u00f3n no fusionadas. Este commit permaneci\u00f3 en el almac\u00e9n de objetos git del repositorio, y cualquier flujo de trabajo que hiciera referencia a @v5 lo recuperar\u00eda y ejecutar\u00eda. Esto es un compromiso de la cadena de suministro mediante envenenamiento de etiquetas. Cualquier flujo de trabajo de GitHub Actions que hiciera referencia a xygeni/xygeni-action@v5 durante la ventana afectada (aproximadamente del 3 al 10 de marzo de 2026) ejecut\u00f3 un implante C2 que otorg\u00f3 al atacante ejecuci\u00f3n arbitraria de comandos en el ejecutor de CI por hasta 180 segundos por ejecuci\u00f3n de flujo de trabajo."
    }
  ],
  "id": "CVE-2026-31976",
  "lastModified": "2026-03-16T19:02:12.933",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "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": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-11T20:16:17.440",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking"
      ],
      "url": "https://github.com/xygeni/xygeni-action/issues/54"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory",
        "Patch"
      ],
      "url": "https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-506"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

CVE-2026-31976 (GCVE-0-2026-31976)

Vulnerability from cvelistv5 – Published: 2026-03-11 19:44 – Updated: 2026-03-12 19:54

Title

xygeni-action v5 tag poisoned with C2 backdoor

Summary

Severity ?

9.3 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CWE

CWE-506 - Embedded Malicious Code

Assigner

GitHub_M

References

URL

Tags

	https://github.com/xygeni/xygeni-action/security/…	x_refsource_CONFIRM
	https://github.com/xygeni/xygeni-action/issues/54	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	xygeni	xygeni-action	Affected: >= March 3, 2026, <= March 10, 2026

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-31976",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-12T19:54:48.032219Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-12T19:54:54.608Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "xygeni-action",
          "vendor": "xygeni",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= March 3, 2026, \u003c= March 10, 2026"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "xygeni-action is the GitHub Action for Xygeni Scanner. On March 3, 2026, an attacker with access to compromised credentials created a series of pull requests (#46, #47, #48) injecting obfuscated shell code into action.yml. The PRs were blocked by branch protection rules and never merged into the main branch. However, the attacker used the compromised GitHub App credentials to move the mutable v5 tag to point at the malicious commit (4bf1d4e19ad81a3e8d4063755ae0f482dd3baf12) from one of the unmerged PRs. This commit remained in the repository\u0027s git object store, and any workflow referencing @v5 would fetch and execute it. This is a supply chain compromise via tag poisoning. Any GitHub Actions workflow referencing xygeni/xygeni-action@v5 during the affected window (approximately March 3\u201310, 2026) executed a C2 implant that granted the attacker arbitrary command execution on the CI runner for up to 180 seconds per workflow run."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-506",
              "description": "CWE-506: Embedded Malicious Code",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-11T19:44:38.643Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh"
        },
        {
          "name": "https://github.com/xygeni/xygeni-action/issues/54",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/xygeni/xygeni-action/issues/54"
        }
      ],
      "source": {
        "advisory": "GHSA-f8q5-h5qh-33mh",
        "discovery": "UNKNOWN"
      },
      "title": "xygeni-action v5 tag poisoned with C2 backdoor"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-31976",
    "datePublished": "2026-03-11T19:44:38.643Z",
    "dateReserved": "2026-03-10T15:40:10.487Z",
    "dateUpdated": "2026-03-12T19:54:54.608Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

FKIE_CVE-2026-31976

CVE-2026-31976 (GCVE-0-2026-31976)

Tags

Sightings

Nomenclature