CVE-2026-96641
Full vulnerability record from the local CVENow database.
Description
Pillow is a Python imaging library. Prior to 13.0.0, PILfont text-width accumulation in src/_imaging.c checks positive glyph advances against INT_MAX but does not check negative advances against INT_MIN. Repeating a signed 16-bit advance of -32768 can therefore execute a signed C integer overflow in xsize += dx, producing a large positive width from a negative mathematical result. Applications that use getlength(), getsize(), or derived layout, quota, serialization, or allocation calculations can experience logic-integrity errors or resource consumption, while the high-level mask path commonly retains a decompression-bomb check. This issue is fixed in version 13.0.0.
Severity
MEDIUM
CVSS score
6.5
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-10-21 21:20:32.500000
Last modified
2026-10-28 02:17:08.123000
View original CVE JSON
{
"id": "CVE-2026-96641",
"sourceIdentifier": "[email protected]",
"published": "2026-10-21T21:20:32.500",
"lastModified": "2026-10-28T02:17:08.123",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Pillow is a Python imaging library. Prior to 13.0.0, PILfont text-width accumulation in src/_imaging.c checks positive glyph advances against INT_MAX but does not check negative advances against INT_MIN. Repeating a signed 16-bit advance of -32768 can therefore execute a signed C integer overflow in xsize += dx, producing a large positive width from a negative mathematical result. Applications that use getlength(), getsize(), or derived layout, quota, serialization, or allocation calculations can experience logic-integrity errors or resource consumption, while the high-level mask path commonly retains a decompression-bomb check. This issue is fixed in version 13.0.0."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "python-pillow",
"product": "Pillow",
"versions": [
{
"version": "< 13.0.0",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "REQUIRED",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-28T01:50:02.182605Z",
"id": "CVE-2026-96641",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-190"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*",
"versionEndExcluding": "13.0.0",
"matchCriteriaId": "EB9056BC-A940-47D5-957B-7BA438FA0D58"
}
]
}
]
}
],
"references": [
{
"url": "https://github.com/python-pillow/Pillow/commit/80de4be9e38d3a6148dd4d8491eb80cd12b760a4",
"source": "[email protected]",
"tags": [
"Patch"
]
},
{
"url": "https://github.com/python-pillow/Pillow/pull/10010",
"source": "[email protected]",
"tags": [
"Issue Tracking"
]
},
{
"url": "https://github.com/python-pillow/Pillow/releases/tag/13.0.0",
"source": "[email protected]",
"tags": [
"Release Notes"
]
},
{
"url": "https://github.com/python-pillow/Pillow/security/advisories/GHSA-4rm8-3hmm-39fg",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
}
]
}