CVE-2026-103680
A flaw was found in tnef. A heap-based buffer overflow can occur in the find_free_number() function when generating numbered backup suffixes for duplicate filenames. When numbered backups are enabled and file overwriting is disabled, an attacker can supply a specially crafted Transport Neutral Encapsulation Format (TNEF) file with an excessive number of colliding attachment filenames, causing the numeric counter to write past the allocated memory buffer. This issue may result in an application crash, leading to a Denial of Service (DoS), or potentially arbitrary code execution.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- Puntuación base: 6.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.33%
- Percentil entre todas las CVEs puntuadas: 24
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1203Exploitation for Client Executionexecution85 % - Impacto principal
T1499.004Application or System Exploitationimpact80 % - Impacto secundario
T1059Command and Scripting Interpreterexecution35 %
Requiere interacción del usuario (UI:R) para procesar archivo TNEF malicioso. Buffer overflow heap puede causar DoS o ejecución de código según la descripción.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-787
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-103680",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-103680",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-10-01T14:57:56.123447Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "patrick@puiterwijk.org",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 3.1,
"attackVector": "NETWORK",
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "HIGH",
"availabilityImpact": "LOW",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 1.6
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 6.5,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 2.8
}
]
},
"affected": [
{
"source": "patrick@puiterwijk.org",
"affectedData": [
{
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "1.4.18"
}
],
"packageName": "tnef",
"collectionURL": "https://github.com/verdammelt/tnef",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-10-01T12:17:15.810",
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-103680",
"tags": [
"Third Party Advisory"
],
"source": "patrick@puiterwijk.org"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2544478",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "patrick@puiterwijk.org"
},
{
"url": "https://github.com/verdammelt/tnef",
"tags": [
"Product"
],
"source": "patrick@puiterwijk.org"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "patrick@puiterwijk.org",
"description": [
{
"lang": "en",
"value": "CWE-787"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in tnef. A heap-based buffer overflow can occur in the find_free_number() function when generating numbered backup suffixes for duplicate filenames. When numbered backups are enabled and file overwriting is disabled, an attacker can supply a specially crafted Transport Neutral Encapsulation Format (TNEF) file with an excessive number of colliding attachment filenames, causing the numeric counter to write past the allocated memory buffer. This issue may result in an application crash, leading to a Denial of Service (DoS), or potentially arbitrary code execution."
}
],
"lastModified": "2026-10-05T13:42:10.633",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:tnef_project:tnef:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D0971079-1960-4691-BA33-FDECDAAB7233",
"versionEndIncluding": "1.4.18"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "patrick@puiterwijk.org"
}