CVE-2010-1866
Status: ModifiedCritical (9.8)—💥 Exploit
The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a denial of service (crash) and possibly trigger memory corruption via a negative chunk size, which bypasses a signed comparison, related to an integer overflow in the chunk size decoder.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Base score: 9.8
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 6.72%
- Percentile among all scored CVEs: 94
- Score date: 10/8/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
💥 Public exploits
Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.
- Published on Exploit-DB · PHP 5.3 - 'PHP_dechunk()' HTTP Chunked Encoding Integer Overflow (5/2/2010)
Affected technologies (3)
CWEs
- CWE-190
References
- http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html
- http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.html
- http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html
- http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.html
Raw JSON (NVD)
Show
{
"id": "CVE-2010-1866",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 7.5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
"authentication": "NONE",
"integrityImpact": "PARTIAL",
"accessComplexity": "LOW",
"availabilityImpact": "PARTIAL",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 6.4,
"baseSeverity": "HIGH",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"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"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2010-05-07T23:00:01.860",
"references": [
{
"url": "http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html",
"tags": [
"Mailing List"
],
"source": "cve@mitre.org"
},
{
"url": "http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.html",
"tags": [
"Broken Link",
"Exploit"
],
"source": "cve@mitre.org"
},
{
"url": "http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html",
"tags": [
"Mailing List"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://php-security.org/2010/05/02/mops-2010-003-php-dechunk-filter-signed-comparison-vulnerability/index.html",
"tags": [
"Broken Link",
"Exploit"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-190"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a denial of service (crash) and possibly trigger memory corruption via a negative chunk size, which bypasses a signed comparison, related to an integer overflow in the chunk size decoder."
},
{
"lang": "es",
"value": "El filtro dechunk en PHP 5.3 hasta v.5.3.2, cuando se decodifica un cadena HTTP fragmentada, permite a atacantes depediendo del contexto provocar una denegación de servicio (caída) y posiblemente una corrupción de memoria mediante un tamaño de fragmento negativo, lo que evita la comparación de signo, relativo a un desbordamiento de entero en el decodificados de tamaño del fragmento."
}
],
"lastModified": "2026-06-16T23:19:29.190",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:php:php:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "2CFE4CC6-A7C2-414D-9740-45E93282D50A",
"versionEndIncluding": "5.3.2",
"versionStartIncluding": "5.3.0"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:opensuse:opensuse:11.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "FBF7B6A8-3DF9-46EC-A90E-6EF68C39F883"
},
{
"criteria": "cpe:2.3:o:opensuse:opensuse:11.2:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A01C8B7E-EB19-40EA-B1D2-9AE5EA536C95"
},
{
"criteria": "cpe:2.3:o:opensuse:opensuse:11.3:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5646FDE9-CF21-46A9-B89D-F5BBDB4249AF"
},
{
"criteria": "cpe:2.3:o:suse:linux_enterprise:10.0:sp3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1193A7E6-DCB4-4E79-A509-1D6948153A57"
},
{
"criteria": "cpe:2.3:o:suse:linux_enterprise:11.0:-:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1608E282-2E96-4447-848D-DBE915DB0EF9"
},
{
"criteria": "cpe:2.3:o:suse:linux_enterprise:11.0:sp1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4500161F-13A0-4369-B93A-778B34E7F005"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org"
}