CVE-2026-47321
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception.
Leer descripción completaMostrar menos
It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
Detalles técnicos trazas, registros y código del informe original
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
.setDecompressRatioMinSize(100_000);CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.49%
- Percentil entre todas las CVEs puntuadas: 40
- Fecha de la puntuación: 4/10/2026
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
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
Aplicación expuesta en red (AV:N) vulnerable a descompresión ZIP sin límite de tamaño, causando agotamiento de memoria (DoS por consumo de recursos). Sin autenticación ni interacción.
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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-409, CWE-789
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-47321",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-47321",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-21T14:00:30.976651Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security@apache.org",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security@apache.org",
"affectedData": [
{
"vendor": "Apache Software Foundation",
"product": "Apache MINA",
"versions": [
{
"status": "affected",
"version": "2.2.0",
"lessThan": "2.2.8",
"versionType": "maven"
},
{
"status": "affected",
"version": "2.1.0",
"lessThan": "2.1.13",
"versionType": "maven"
},
{
"status": "affected",
"version": "2.0.0",
"lessThan": "2.0.29",
"versionType": "maven"
}
],
"packageName": "org.apache.mina:mina-filter-compression",
"collectionURL": "https://repo.maven.apache.org/maven2",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-09-21T08:16:37.520",
"references": [
{
"url": "https://lists.apache.org/thread/y7xj1bl8qo47p9bktb11hg5v6k1d4dyj",
"source": "security@apache.org"
},
{
"url": "http://www.openwall.com/lists/oss-security/2026/09/21/1",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "security@apache.org",
"description": [
{
"lang": "en",
"value": "CWE-409"
},
{
"lang": "en",
"value": "CWE-789"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.\n\nSome compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.\n\n\n\n\nThe fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)\n\n\n\n\nFor application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:\n\n\n\n\npublic CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.\n\n\n\n\nHere are the additional constructor:\n\n\n\n\n\n\npublic CompressionFilter(final boolean compressInbound, final boolean compressOutbound,\n\n\n\n final int compressionLevel, final int maxDecompressedSize,\n\n\n\n final long maxDecompressRatio, final long decompressRatioMinSize)\n\n\n\n\n\n\n\n\nAlso note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:\n\n\n\n\n\n\n CompressionFilter compressionFilter = new CompressionFilter()\n\n .setCompressionLevel(Zlib.COMPRESSION_MAX)\n\n .setMaxDecompressedSize(1_000_000)\n\n .setMaxDecompressRatio(100).\n\n .setDecompressRatioMinSize(100_000); \n\n\n\n\n\n\n\n\n\nApplications using Apache MINA are advised to upgrade and configure their CompressionFilter instance."
}
],
"lastModified": "2026-09-21T19:17:06.247",
"sourceIdentifier": "security@apache.org"
}