CVE-2026-31976

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{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-31976", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-03-12T19:54:48.032219Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-12T19:54:51.816Z"}}], "cna": {"title": "xygeni-action v5 tag poisoned with C2 backdoor", "source": {"advisory": "GHSA-f8q5-h5qh-33mh", "discovery": "UNKNOWN"}, "metrics": [{"cvssV4_0": {"version": "4.0", "baseScore": 9.3, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "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", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH"}}], "affected": [{"vendor": "xygeni", "product": "xygeni-action", "versions": [{"status": "affected", "version": ">= March 3, 2026, <= March 10, 2026"}]}], "references": [{"url": "https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh", "name": "https://github.com/xygeni/xygeni-action/security/advisories/GHSA-f8q5-h5qh-33mh", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/xygeni/xygeni-action/issues/54", "name": "https://github.com/xygeni/xygeni-action/issues/54", "tags": ["x_refsource_MISC"]}], "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-506", "description": "CWE-506: Embedded Malicious Code"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-11T19:44:38.643Z"}}}, "cveMetadata": {"cveId": "CVE-2026-31976", "state": "PUBLISHED", "dateUpdated": "2026-03-12T19:54:54.608Z", "dateReserved": "2026-03-10T15:40:10.487Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-03-11T19:44:38.643Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "xygeni-action", "vendor": "xygeni", "versions": [{"status": "affected", "version": ">= March 3, 2026, <= March 10, 2026"}]}], "source": "security-advisories@github.com"}], "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'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."}], "id": "CVE-2026-31976", "lastModified": "2026-06-17T10:34:52.610", "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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-31976", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-03-12T19:54:48.032219Z", "version": "2.0.3"}}]}, "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": ["Patch", "Vendor Advisory"], "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": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[March 3, 2026, March 10, 2026]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "xygeni-action", "source": "cna", "vendor": "xygeni"}, "product": "xygeni-action", "vendor": "xygeni"}], "analysis": {"en": {"generated_at": "2026-03-17T15:46:02.375734+00:00", "value": {"mitigation_remediation": ["Switch the action reference from the mutable tag '@v5' to a fixed commit SHA or a stable release tag after verifying its integrity", "Check the repository and vendor advisories for a patched release removing the injected code, and update the workflow accordingly", "Review and tighten GitHub App permissions and tag protection rules to prevent unauthorized tag changes, and monitor CI runners for anomalous activity"], "summary": {"action": "Apply Patch", "impact": "Remote Code Execution on CI Runner"}, "threat_synthesis": {"affected_systems": "The affected product is the xygeni-action GitHub Action for the Xygeni Scanner, indicated by the vendor product pair xygeni:xygeni-action. The specific vulnerability impacts the mutable @v5 tag; any workflow that uses xygeni/xygeni-action@v5 during the specified window is at risk. No other versions or tags are listed in the vulnerable commit, so the risk applies exclusively to references that resolve to the malicious v5 tag during that time.", "description_and_impact": "The vulnerability is a supply\u2011chain compromise caused by an attacker who injected obfuscated shell code into the action.yml of the xygeni/xygeni\u2011action GitHub Action. By moving the mutable @v5 tag to point at the malicious commit, any workflow that references xygeni/xygeni-action@v5 during the affected window (March 3\u201310, 2026) will fetch and execute that code. The injected payload is a command\u2011and\u2011control implant that grants the attacker arbitrary command execution on the GitHub Actions CI runner for up to 180 seconds on each workflow run. This is an instance of CWE\u2011506 (Exposed Secret in Source Code) and results in full Remote Code Execution on the build environment.", "risk_and_exploitability": "The CVSS score of 9.3 indicates a high\u2011severity flaw, and the EPSS score of less than 1% suggests limited public exploitation data so far. The vulnerability is not in the CISA KEV catalog. The attack vector is remote, via a compromised GitHub App credential that allowed the attacker to alter tag references. Once a workflow references the poisoned tag, the malicious code executes with the same permissions as the workflow runner, enabling arbitrary command execution. Organizations that use the default @v5 reference during the affected period faced a significant risk of compromise."}}}}, "created": "2026-03-12T09:56:26.518179+00:00", "updated": "2026-03-23T09:55:14.960910+00:00", "vendors": ["xygeni", "xygeni$PRODUCT$xygeni-action"]}