Medium
pypdf, pypdf2 — security advisory
pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.
- Products
- pypdf, pypdf2
- Affected versions
- 1.23+git20141008-1, 1.25.1-1, 1.25.1-1ubuntu0.1~esm1, 1.25.1-1ubuntu0.1~esm2, 1.26.0-2, 1.26.0-2ubuntu0.1~esm1, 1.26.0-2ubuntu0.1~esm2, 1.26.0-3ubuntu1, 1.26.0-3ubuntu1.20.04.1, 1.26.0-3ubuntu1.20.04.2, 1.26.0-4, 1.26.0-4ubuntu0.22.04.1, 1.26.0-4ubuntu0.22.04.2, 2.12.1-3, 2.12.1-4, 3.17.4-1, 3.4.1-1, 4.0.0-1, 4.0.1-1, 4.0.2-1, 5.4.0-1, 6.9.2-1, 6.9.2-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-84311
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:22 UTC · Revision 1
Source evidence
pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.
osv:UBUNTU-CVE-2026-84311
pypdf2
Fixed versions: Not specified
pypdf2
Fixed versions: Not specified
pypdf2
Fixed versions: Not specified
pypdf2
Fixed versions: Not specified
pypdf
Fixed versions: Not specified
pypdf2
Fixed versions: Not specified
pypdf
Fixed versions: Not specified
pypdf
Fixed versions: Not specified
Complete source record
{
"id": "a599f2ac6b4fa1bb4ef56bafe5ebf5e988a47bcf5aafd8cdbd88bf5afe89e9a6",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-84311",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-84311",
"summary": "pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.",
"evidence": "osv:UBUNTU-CVE-2026-84311",
"products": [
{
"name": {
"value": "pypdf2",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.23+git20141008-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.25.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.25.1-1ubuntu0.1~esm1",
"evidence": "/affected/0/versions"
},
{
"value": "1.25.1-1ubuntu0.1~esm2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "1.26.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "1.26.0-2ubuntu0.1~esm1",
"evidence": "/affected/1/versions"
},
{
"value": "1.26.0-2ubuntu0.1~esm2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
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"evidence": "/affected/2/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "1.26.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "1.26.0-3ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "1.26.0-3ubuntu1.20.04.1",
"evidence": "/affected/2/versions"
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{
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"evidence": "/affected/2/versions"
}
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},
{
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"evidence": "/affected/3/package/name"
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"affected_versions": [
{
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"evidence": "/affected/3/versions"
},
{
"value": "1.26.0-4ubuntu0.22.04.1",
"evidence": "/affected/3/versions"
},
{
"value": "1.26.0-4ubuntu0.22.04.2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
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"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
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"evidence": "/affected/4/versions"
},
{
"value": "3.17.4-1",
"evidence": "/affected/4/versions"
},
{
"value": "4.0.0-1",
"evidence": "/affected/4/versions"
},
{
"value": "4.0.1-1",
"evidence": "/affected/4/versions"
},
{
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"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "pypdf2",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.12.1-3",
"evidence": "/affected/5/versions"
},
{
"value": "2.12.1-4",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "pypdf",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.9.2-1",
"evidence": "/affected/6/versions"
},
{
"value": "6.9.2-2",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
"value": "pypdf",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.4.0-1",
"evidence": "/affected/7/versions"
},
{
"value": "6.9.2-1",
"evidence": "/affected/7/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-84311",
"aliases": [
"UBUNTU-CVE-2026-84311"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pypdf2",
"purl": "pkg:deb/ubuntu/pypdf2?arch=source&distro=esm-apps%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
"1.23+git20141008-1",
"1.25.1-1",
"1.25.1-1ubuntu0.1~esm1",
"1.25.1-1ubuntu0.1~esm2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84311.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "python-pypdf2",
"binary_version": "1.25.1-1ubuntu0.1~esm2"
},
{
"binary_name": "python3-pypdf2",
"binary_version": "1.25.1-1ubuntu0.1~esm2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pypdf2",
"purl": "pkg:deb/ubuntu/pypdf2?arch=source&distro=esm-apps%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"1.26.0-2",
"1.26.0-2ubuntu0.1~esm1",
"1.26.0-2ubuntu0.1~esm2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-84311.json"
},
"ecosystem_specific": {
"binaries": [
{
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"binary_version": "1.26.0-2ubuntu0.1~esm2"
},
{
"binary_name": "python3-pypdf2",
"binary_version": "1.26.0-2ubuntu0.1~esm2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
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],
"package": {
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"purl": "pkg:deb/ubuntu/pypdf2?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"1.26.0-2",
"1.26.0-3ubuntu1",
"1.26.0-3ubuntu1.20.04.1",
"1.26.0-3ubuntu1.20.04.2"
],
"database_specific": {
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},
"ecosystem_specific": {
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"binary_version": "1.26.0-3ubuntu1.20.04.2"
},
{
"binary_name": "python3-pypdf2",
"binary_version": "1.26.0-3ubuntu1.20.04.2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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],
"package": {
"name": "pypdf2",
"purl": "pkg:deb/ubuntu/pypdf2?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"1.26.0-4",
"1.26.0-4ubuntu0.22.04.1",
"1.26.0-4ubuntu0.22.04.2"
],
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},
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"3.17.4-1",
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],
"modified": "2026-10-17T13:01:12.306799346Z",
"provider": "osv",
"upstream": [
"CVE-2026-84311"
],
"references": [
"https://ubuntu.com/security/CVE-2026-84311",
"https://www.cve.org/CVERecord?id=CVE-2026-84311",
"https://bugzilla.redhat.com/show_bug.cgi?id=2527050"
]
},
"related_cves": [
{
"value": "CVE-2026-84311",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361229,
"published_at": "2026-09-01T21:18:00+00:00"
}