CVE-2026-28525
Full vulnerability record from the local CVENow database.
Description
SWUpdate contains an integer underflow vulnerability in the multipart upload parser in mongoose_multipart.c that allows unauthenticated attackers to cause a denial of service by sending a crafted HTTP POST request to /upload with a malformed multipart boundary and controlled TCP stream timing. Attackers can trigger an integer underflow in the mg_http_multipart_continue_wait_for_chunk() function when the buffer length falls within a specific range, causing an out-of-bounds heap read past the allocated receive buffer to a local IPC socket.
Severity
HIGH
CVSS score
8.2
(v4.0)
Vulnerability status
Analyzed
Source identifier
Published
2026-04-23 21:16:05.367000
Last modified
2026-10-26 21:10:00.170000
View original CVE JSON
{
"id": "CVE-2026-28525",
"sourceIdentifier": "[email protected]",
"published": "2026-04-23T21:16:05.367",
"lastModified": "2026-10-26T21:10:00.170",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "SWUpdate contains an integer underflow vulnerability in the multipart upload parser in mongoose_multipart.c that allows unauthenticated attackers to cause a denial of service by sending a crafted HTTP POST request to /upload with a malformed multipart boundary and controlled TCP stream timing. Attackers can trigger an integer underflow in the mg_http_multipart_continue_wait_for_chunk() function when the buffer length falls within a specific range, causing an out-of-bounds heap read past the allocated receive buffer to a local IPC socket."
},
{
"lang": "es",
"value": "SWUpdate contiene una vulnerabilidad de desbordamiento negativo de enteros en el analizador de carga multiparte en mongoose_multipart.c que permite a atacantes no autenticados causar una denegación de servicio enviando una solicitud HTTP POST manipulada a /upload con un límite multiparte malformado y una temporización controlada del flujo TCP. Los atacantes pueden desencadenar un desbordamiento negativo de enteros en la función mg_http_multipart_continue_wait_for_chunk() cuando la longitud del búfer cae dentro de un rango específico, causando una lectura de pila fuera de límites que escribe datos más allá del búfer de recepción asignado a un socket IPC local."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "sbabic",
"product": "swupdate",
"defaultStatus": "unaffected",
"repo": "https://github.com/sbabic/swupdate",
"packageURL": "pkg:github/sbabic/swupdate",
"versions": [
{
"version": "0",
"lessThanOrEqual": "2025.12",
"versionType": "custom",
"status": "affected"
},
{
"version": "beee2dc0feef1cfe84f1aa6fc980e104b2e47a74",
"versionType": "git",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/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",
"baseScore": 8.2,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H",
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "CHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.2,
"impactScore": 4.0
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-04-25T01:32:10.498553Z",
"id": "CVE-2026-28525",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-125"
},
{
"lang": "en",
"value": "CWE-191"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:swupdate:swupdate:*:*:*:*:*:*:*:*",
"versionEndIncluding": "2025.12",
"matchCriteriaId": "B50CD24D-4B0B-49F0-88BD-EA0BA3E3A30F"
}
]
}
]
}
],
"references": [
{
"url": "https://github.com/sbabic/swupdate/commit/beee2dc0feef1cfe84f1aa6fc980e104b2e47a74",
"source": "[email protected]",
"tags": [
"Patch"
]
},
{
"url": "https://www.vulncheck.com/advisories/swupdate-integer-underflow-in-multipart-upload-parser",
"source": "[email protected]",
"tags": [
"Third Party Advisory"
]
}
]
}