CVE-2026-48156 MEDIUM

CVE-2026-48156: pypdf: Possible long runtimes for zero-only width values in cross-reference streams

Vendor Py-Pdf

Product pypdf

Weakness CWE-834

Published May 28, 2026

Last update May 30, 2026

View on NVD All CVEs

CVSS base score

5.1/10

Attack vector Local

Attack complexity Low

Privileges required None

User interaction None

Confidentiality —

Integrity —

CVSS vector

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

What the vulnerability does

01Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.

Key dates

02Disclosure timeline

May 28, 2026 CVE published

May 30, 2026 Record updated

External resources

03References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2026-48156 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/834.html

Related vulnerabilities

04Related CVE

CVE-2024-4227 gSOAP: Vulnerable to specially crafted unencrypted SDC messages CVE-2026-41168 pypdf has possible long runtimes for wrong size values in cross-reference and object streams CVE-2025-62707 pypdf affected by possible infinite loop when reading DCT inline images without EOF marker CVE-2025-6714 Incorrect Handling of incomplete data may prevent mongoS from Accepting New Connections CVE-2021-35515 Apache Commons Compress 1.6 to 1.20 denial of service vulnerability