pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop when cloning or duplicating a crafted cyclic DictionaryObject. Clone traversal checked generated destination references rather than the original source references, allowing some source cycles to evade the visited-object check. This issue is fixed in version 6.21.4.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-835"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/119xxx/CVE-2026-119205.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "6.21.4"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "f176db1a1f7f9af3e472e69a843ef1175653b044"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "6.21.4",
"range": [
{
"fixed": "b2c3fa2ee689f582a0de256a45e30bd96c68f807"
}
],
"source": "REFERENCES_TAG"
}
]
}