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_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33123.json",
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-400",
"CWE-407"
]
}{
"cpe": "cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*",
"source": [
"AFFECTED_FIELD",
"CPE_RANGE",
"REFERENCES"
],
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "6.9.1"
}
]
}