Medium
pypdf — security advisory
pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.
- Products
- pypdf
- Affected versions
- 3.17.4-1, 3.4.1-1, 4.0.0-1, 4.0.1-1, 4.0.2-1, 4.3.1-1, 5.4.0-1, 6.9.2-1, 6.9.2-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-33123
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:59 UTC · Revision 1
Source evidence
pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.
osv:UBUNTU-CVE-2026-33123
pypdf
Fixed versions: Not specified
pypdf
Fixed versions: Not specified
pypdf
Fixed versions: Not specified
pypdf
Fixed versions: Not specified
Complete source record
{
"id": "95a3f34aa87aea693c255136aebcc0ee43703126598d6c8861399fadc5f497e5",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-33123",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-33123",
"summary": "pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.",
"evidence": "osv:UBUNTU-CVE-2026-33123",
"products": [
{
"name": {
"value": "pypdf",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.4.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.17.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.2-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "pypdf",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.3.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.4.0-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "pypdf",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.9.2-1",
"evidence": "/affected/2/versions"
},
{
"value": "6.9.2-2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "pypdf",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.4.0-1",
"evidence": "/affected/3/versions"
},
{
"value": "6.9.2-1",
"evidence": "/affected/3/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-33123",
"aliases": [
"UBUNTU-CVE-2026-33123"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pypdf",
"purl": "pkg:deb/ubuntu/pypdf?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"3.4.1-1",
"3.17.4-1",
"4.0.0-1",
"4.0.1-1",
"4.0.2-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-pypdf",
"binary_version": "4.0.2-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pypdf",
"purl": "pkg:deb/ubuntu/pypdf?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"4.3.1-1",
"5.4.0-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-pypdf",
"binary_version": "5.4.0-1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pypdf",
"purl": "pkg:deb/ubuntu/pypdf?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"6.9.2-1",
"6.9.2-2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-pypdf",
"binary_version": "6.9.2-2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pypdf",
"purl": "pkg:deb/ubuntu/pypdf?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"5.4.0-1",
"6.9.2-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33123.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python3-pypdf",
"binary_version": "6.9.2-1"
}
]
}
}
],
"modified": "2026-10-17T12:59:58.800297924Z",
"provider": "osv",
"upstream": [
"CVE-2026-33123"
],
"references": [
"https://ubuntu.com/security/CVE-2026-33123",
"https://www.cve.org/CVERecord?id=CVE-2026-33123",
"https://github.com/py-pdf/pypdf/pull/3686",
"https://github.com/py-pdf/pypdf/releases/tag/6.9.1",
"https://github.com/py-pdf/pypdf/security/advisories/GHSA-qpxp-75px-xjcp"
]
},
"related_cves": [
{
"value": "CVE-2026-33123",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 360062,
"published_at": "2026-03-20T10:16:00+00:00"
}