CVE-2026-31976

{"id": "CVE-2026-31976", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "published": "2026-03-11T20:16:17.440", "references": [{"url": "https://github.com/xygeni/xygeni-action/issues/54", "tags": ["Issue Tracking"], "source": "security-advisories@github.com"}, {"url": "https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh", "tags": ["Vendor Advisory", "Patch"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-506"}]}], "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'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\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."}], "lastModified": "2026-03-16T19:02:12.933", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:xygeni:xygeni-action:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "432E19E2-DDB5-4EBB-A540-A07106448E76", "versionEndIncluding": "6.4.0", "versionStartIncluding": "5.38.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}