CVE-2026-82398
Full vulnerability record from the local CVENow database.
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.
Severity
MEDIUM
CVSS score
6.9
(v4.0)
Vulnerability status
Analyzed
Source identifier
Published
2026-08-31 22:17:23.083000
Last modified
2026-11-02 16:06:04.477000
View original CVE JSON
{
"id": "CVE-2026-82398",
"sourceIdentifier": "[email protected]",
"published": "2026-08-31T22:17:23.083",
"lastModified": "2026-11-02T16:06:04.477",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "py-pdf",
"product": "pypdf",
"versions": [
{
"version": "< 6.15.0",
"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"
}
}
],
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "LOW"
},
"exploitabilityScore": 3.9,
"impactScore": 1.4
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-09-01T14:18:26.492095Z",
"id": "CVE-2026-82398",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-407"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.15.0",
"matchCriteriaId": "1AB8CD41-FC65-43C7-A679-AC2250461FA7"
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],
"references": [
{
"url": "https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa",
"source": "[email protected]",
"tags": [
"Patch"
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},
{
"url": "https://github.com/py-pdf/pypdf/pull/3947",
"source": "[email protected]",
"tags": [
"Patch"
]
},
{
"url": "https://github.com/py-pdf/pypdf/releases/tag/6.15.0",
"source": "[email protected]",
"tags": [
"Release Notes"
]
},
{
"url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m",
"source": "[email protected]",
"tags": [
"Patch",
"Vendor Advisory"
]
}
]
}