CVE-2026-28804

low-risk

Published 2026-03-06

pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. This issue has been patched in version 6.7.5.

Do I need to act?

0.05% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 5.3/10 Medium

NETWORK / LOW complexity

Affected Products (1)

Pypdf

Affected Vendors

Pypdf Project

References (4)

Patch https://github.com/py-pdf/pypdf/commit/648c627d2657447dfb1773412af05a0a5103b98f

Issue Tracking https://github.com/py-pdf/pypdf/pull/3666

Product https://github.com/py-pdf/pypdf/releases/tag/6.7.5

Patch https://github.com/py-pdf/pypdf/security/advisories/GHSA-9m86-7pmv-2852

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low-risk

Severity 21/34 · High

Exploitability 0/34 · Minimal

Exposure 5/34 · Minimal