CVE-2026-59881
Full vulnerability record from the local CVENow database.
Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.
Severity
MEDIUM
CVSS score
6.9
(v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-07-30 19:18:33.597000
Last modified
2026-10-23 22:10:00.160000
View original CVE JSON
{
"id": "CVE-2026-59881",
"sourceIdentifier": "[email protected]",
"published": "2026-07-30T19:18:33.597",
"lastModified": "2026-10-23T22:10:00.160",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2."
},
{
"lang": "es",
"value": "AIOHTTP es un framework HTTP cliente/servidor asíncrono para asyncio y Python. Antes de la versión 3.14.2, el cliente WebSocket acepta y descomprime tramas con el bit RSV1 activado incluso cuando la extensión permessage-deflate no fue negociada, permitiendo que un servidor malicioso cause un consumo inesperado de CPU y memoria. Este problema está solucionado en la versión 3.14.2."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "aio-libs",
"product": "aiohttp",
"versions": [
{
"version": "< 3.14.2",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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": 6.9,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "LOW",
"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"
}
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-30T18:35:32.868187Z",
"id": "CVE-2026-59881",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-20"
}
]
}
],
"references": [
{
"url": "http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2",
"source": "[email protected]"
},
{
"url": "https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6",
"source": "[email protected]"
},
{
"url": "https://github.com/aio-libs/aiohttp/pull/12978",
"source": "[email protected]"
},
{
"url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7",
"source": "[email protected]"
}
]
}