CVE-2026-40394

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Durante la actualizaci\u00f3n, se realiza una asignaci\u00f3n de b\u00fafer para reservar espacio para enviar tramas al cliente. Esta asignaci\u00f3n dividir\u00eda el espacio de trabajo original y, dependiendo de la cantidad de datos precargados, la siguiente recuperaci\u00f3n podr\u00eda realizar una operaci\u00f3n de pipelining que agotar\u00eda el espacio de trabajo."}], "id": "CVE-2026-40394", "lastModified": "2026-10-26T21:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 4.0, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "cve@mitre.org", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40394", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-13T15:45:49.035659Z", "version": "2.0.3"}}]}, "published": "2026-04-12T20:16:17.857", "references": [{"source": "cve@mitre.org", "tags": ["Vendor Advisory"], "url": "https://docs.varnish-software.com/security/VEV00002/"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-670"}], "source": "cve@mitre.org", "type": "Secondary"}]}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[9.0.0,9.0.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "inferred", "scores": [{"score": 100.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Varnish Cache", "source": "cna", "vendor": "varnish-software"}, "product": "varnish_cache", "vendor": "varnish-software"}], "analysis": {"en": {"generated_at": "2026-04-14T01:38:51.704129+00:00", "value": {"mitigation_remediation": ["Upgrade Varnish Cache to version 9.0.1 or later", "Upgrade Varnish Enterprise to version 6.0.16r11 or later"], "summary": {"action": "Immediate Patch", "impact": "Denial of Service"}, "threat_synthesis": {"affected_systems": "Varnish Cache 9 versions prior to 9.0.1 and Varnish Enterprise 6 versions before 6.0.16r11 are affected. The issue applies to environments running Varnish on the corresponding software releases.", "description_and_impact": "The vulnerability in Varnish Cache and Varnish Enterprise allows an attacker to trigger a workspace overflow that causes the daemon to panic and stop serving requests. It stems from a buffer allocation made during the HTTP/2 session upgrade, which, given certain amounts of prefetched data, can deplete available workspace and induce a denial of service. The weakness corresponds to CWE\u2011131 (Incorrect Calculation of Buffer Size) and CWE\u2011670 (Privilege Escalation). The result is loss of service for the affected instance, impacting application availability for all users of the server.", "risk_and_exploitability": "The CVSS score of 4 indicates moderate severity, and the EPSS score of less than 1% suggests low probability of current exploitation. The vulnerability has not been reported in the CISA KEV catalog. The exploit requires connection to the Varnish instance, configuration of an HTTP/2 session, and delivery of prefetched data that triggers the overflow, implying a remote or network\u2011based attack vector."}}}}, "created": "2026-04-13T12:38:14.753647+00:00", "updated": "2026-04-14T16:36:12.163665+00:00", "vendors": ["varnish-software", "varnish-software$PRODUCT$varnish_cache"]}