CVE-2026-28804 — Inefficient Algorithmic Complexity in Pypdf

CWE-407 — Inefficient Algorithmic ComplexityCWE-770 — Allocation of Resources Without Limits or Throttling7 documents6 sources
Severity
6.9MEDIUMNVD
EPSS
0.0%
top 84.77%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Py-pdf PypdfPypdf Project PypdfDebian Pypdf+1 more
Timeline
PublishedMar 6

Description

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.

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Affected Packages6 packages

▶CVEListV5py-pdf/pypdf< 6.7.5
▶debiandebian/pypdf< pypdf 6.9.0-1 (forky)
▶debiandebian/pypdf2< pypdf 6.9.0-1 (forky)
▶NVDpypdf_project/pypdf< 6.7.5
▶PyPIpypdf_project/pypdf< 6.7.5

Patches

Patch: github.com ↗Patch: github.com ↗Patch: github.com ↗

🔴Vulnerability Details

3
OSV
CVE-2026-28804: pypdf is a free and open-source pure-python PDF library↗2026-03-06
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OSV
pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams↗2026-03-02
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GHSA
pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams↗2026-03-02
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📋Vendor Advisories

2
Red Hat
pypdf: pypdf: Denial of Service via crafted PDF with ASCIIHexDecode filter↗2026-03-06
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Debian
CVE-2026-28804: pypdf - pypdf is a free and open-source pure-python PDF library. Prior to version 6.7.5,...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-28804 Impact, Exploitability, and Mitigation Steps | Wiz↗
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