Resource exhaustion in Py-Pdf Pypdf
CVE-2026-31826
pypdf is a free and open-source pure-python PDF library. Prior to 6.8.0, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing a content stream with a rather large /Length value, regardless of the actual data length inside the stream. This vulnerability is fixed in 6.8.0.
EPSS: 0.002 (6.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
Affected products
- Py-pdf Pypdf — versions < 6.8.0
- 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 (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-31826?
- CVE-2026-31826 is a medium-severity vulnerability in Py-Pdf Pypdf, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.5/10. Published 2026-03-10.
- How severe is CVE-2026-31826?
- Medium severity. CVSS v3 base score is 5.5 out of 10.