Medium
pypdf: Manipulated FlateDecode XFA streams can exhaust RAM
Type: advisorySources: OSV
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-27888
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 2 Nov 2026, 18:32 UTC · Revision 1
Source evidence
pypdf: Manipulated FlateDecode XFA streams can exhaust RAM
core-osv · Original sourcePublished 26 Feb 2026, 00:42 UTC
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.
osv:CVE-2026-27888
Complete source record
{
"id": "f3f81bc4353566ea50ad44c0178eff35aac7e3a1f8d8f0bc66d6b46a0c5c39af",
"url": "https://osv.dev/vulnerability/CVE-2026-27888",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "pypdf: Manipulated FlateDecode XFA streams can exhaust RAM",
"summary": "pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.",
"evidence": "osv:CVE-2026-27888",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-27888",
"aliases": [
"CVE-2026-27888",
"GHSA-x7hp-r3qg-r3cj",
"PYSEC-2026-3027"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/py-pdf/pypdf",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "05e6d3c03deaec6b16b53825465537ac9e7a1a14"
},
{
"fixed": "7a4c8246ed48d9d328fb596942271da47b6d109c"
}
],
"database_specific": {
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{
"cpe": "cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*",
"range": [
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{
"fixed": "6.7.3"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "7a4c8246ed48d9d328fb596942271da47b6d109c"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
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}
],
"source": "REFERENCES_TAG",
"original_tag": "6.7.3"
}
]
}
}
],
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"1.27.12",
"1.27.11",
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"1.27.3",
"1.27.2",
"1.27.1",
"1.27.0",
"v1.24",
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"v1.25.1",
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27888.json"
}
}
],
"modified": "2026-10-28T02:30:22.238792249Z",
"provider": "osv",
"references": [
"https://github.com/py-pdf/pypdf/releases/tag/6.7.3",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27888.json",
"https://github.com/py-pdf/pypdf/security/advisories/GHSA-x7hp-r3qg-r3cj",
"https://nvd.nist.gov/vuln/detail/CVE-2026-27888",
"https://github.com/py-pdf/pypdf/commit/7a4c8246ed48d9d328fb596942271da47b6d109c",
"https://github.com/py-pdf/pypdf/pull/3658"
],
"provider_metadata": {
"cwe_ids": [
"CWE-400"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27888.json"
}
},
"related_cves": [
{
"value": "CVE-2026-27888",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 488531,
"published_at": "2026-02-26T00:42:00.542+00:00"
}