Resource exhaustion in Py-Pdf Pypdf
CVE-2026-28351
pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.4, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream using the RunLengthDecode filter. This has been fixed in pypdf 6.7.4. As a workaround, consider applying the changes from PR #3664.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.004 (34.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Py-pdf Pypdf — versions < 6.7.4
- Pypdf_project Pypdf
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-28351?
- CVE-2026-28351 is a medium-severity vulnerability in Py-Pdf Pypdf, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2026-02-27.
- How severe is CVE-2026-28351?
- Medium severity. CVSS v3 base score is 5.3 out of 10.