{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2026-25823", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-03-13T16:03:42.853Z", "dateReserved": "2026-02-06T00:00:00.000Z", "datePublished": "2026-03-12T00:00:00.000Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-03-12T21:28:27.148Z"}, "descriptions": [{"lang": "en", "value": "HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have a stack buffer overflow that leads to a Denial of Service, which can also be exploited to achieve Unauthenticated Remote Code Execution."}], "affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"version": "n/a", "status": "affected"}]}], "references": [{"url": "https://www.hms-networks.com/p/flexy20500-00ma-ewon-flexy-205"}, {"url": "https://hmsnetworks.blob.core.windows.net/nlw/docs/default-source/products/cybersecurity/security-advisory/hms-security-advisory-2026-03-09-001---ewon-several-flexy-and-cosy--vulnerabilities.pdf?sfvrsn=f7c027b8_13"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-121", "lang": "en", "description": "CWE-121 Stack-based Buffer Overflow"}]}], "metrics": [{"cvssV3_1": {"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"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-03-13T16:03:39.579496Z", "id": "CVE-2026-25823", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-13T16:03:42.853Z"}}]}, "dataVersion": "5.2"}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have a stack buffer overflow that leads to a Denial of Service, which can also be exploited to achieve Unauthenticated Remote Code Execution."}, {"lang": "es", "value": "HMS Networks Ewon Flexy con firmware anterior a 15.0s4, Cosy+ con firmware 22.xx anterior a 22.1s6, y Cosy+ con firmware 23.xx anterior a 23.0s3 tienen un desbordamiento de b\u00fafer de pila que conduce a una denegaci\u00f3n de servicio, que tambi\u00e9n puede ser explotado para lograr la ejecuci\u00f3n remota de c\u00f3digo no autenticado."}], "id": "CVE-2026-25823", "lastModified": "2026-04-27T19:18:46.690", "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2026-03-13T19:54:27.790", "references": [{"source": "cve@mitre.org", "url": "https://hmsnetworks.blob.core.windows.net/nlw/docs/default-source/products/cybersecurity/security-advisory/hms-security-advisory-2026-03-09-001---ewon-several-flexy-and-cosy--vulnerabilities.pdf?sfvrsn=f7c027b8_13"}, {"source": "cve@mitre.org", "url": "https://www.hms-networks.com/p/flexy20500-00ma-ewon-flexy-205"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-121"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,22.1s6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,23.0s3)"}}], "enrichment": {"confidence": 80.0, "confidence_source": "inferred", "scores": [{"score": 80.0, "source": "inferred"}, {"score": 87.0, "source": "matching"}]}, "original": {"product": "n/a", "source": "cna", "vendor": "n/a"}, "product": "ewon_cosy", "vendor": "hms-networks"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,15.0s4)"}}], "enrichment": {"confidence": 80.0, "confidence_source": "inferred", "scores": [{"score": 80.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "n/a", "source": "cna", "vendor": "n/a"}, "product": "ewon_flexy", "vendor": "hms-networks"}], "analysis": {"en": {"generated_at": "2026-03-18T15:01:30.825782+00:00", "value": {"mitigation_remediation": ["Upgrade to the latest firmware: Ewon Flexy firmware 15.0s4 or newer; Cosy+ firmware 22.1s6 or newer for 22.xx series; Cosy+ firmware 23.0s3 or newer for 23.xx series.", "If upgrading immediately is not possible, isolate the device from the untrusted network and restrict access to authorized IP ranges only.", "Continuously monitor device logs for anomalous traffic or repeated failure events, and investigate any suspected exploitation attempts."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Affected vendors and products are HMS Networks Ewon Flexy firmware before 15.0s4, Cosy+ firmware 22.xx before 22.1s6, and Cosy+ firmware 23.xx before 23.0s3. No additional vendor-specific version information is provided beyond the firmware version ranges.\n", "description_and_impact": "The vulnerability is a stack buffer overflow (CWE-121) present in HMS Networks Ewon Flexy and Cosy+ devices. Key detail from the CVE description: the overflow can cause a denial of service and, if exploited, can lead to unauthenticated remote code execution. The impact includes loss of availability and potential compromise of confidentiality and integrity if the remote code execution is achieved. The overflow occurs during firmware processing of certain inputs, allowing an attacker to overwrite return addresses and execute arbitrary code.\n", "risk_and_exploitability": "The severity rating is CVSS 9.8, indicating a critical risk. The EPSS score is reported as less than 1%, suggesting a low probability of exploitation at this time. The vulnerability is not listed in the CISA KEV catalog. Based on the description, the attack vector is remote and unauthenticated; an attacker can trigger the overflow from a remote machine without authentication.\n"}}}}, "created": "2026-03-13T09:53:55.955712+00:00", "title": "Stack Buffer Overflow in HMS Networks Ewon Flexy and Cosy+ Firmware Enabling Remote Code Execution", "updated": "2026-03-20T15:36:30.475162+00:00", "vendors": ["hms-networks", "hms-networks$PRODUCT$ewon_cosy", "hms-networks$PRODUCT$ewon_flexy"]}