CVE-2026-27888 — Uncontrolled Resource Consumption in Pypdf

CWE-400 — Uncontrolled Resource ConsumptionCWE-1050 — Excessive Platform Resource Consumption within a Loop7 documents6 sources
Severity
6.6MEDIUMNVD
EPSS
0.1%
top 83.75%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Py-pdf PypdfPypdf Project PypdfDebian Pypdf+1 more
Timeline
PublishedFeb 26

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.

CVSS vector

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

Affected Packages6 packages

▶CVEListV5py-pdf/pypdf< 6.7.3
▶debiandebian/pypdf< pypdf 6.9.0-1 (forky)
▶debiandebian/pypdf2< pypdf 6.9.0-1 (forky)
▶NVDpypdf_project/pypdf< 6.7.3
▶PyPIpypdf_project/pypdf< 6.7.3

Patches

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

🔴Vulnerability Details

3
OSV
CVE-2026-27888: pypdf is a free and open-source pure-python PDF library↗2026-02-26
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GHSA
pypdf: Manipulated FlateDecode XFA streams can exhaust RAM↗2026-02-26
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OSV
pypdf: Manipulated FlateDecode XFA streams can exhaust RAM↗2026-02-26
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📋Vendor Advisories

2
Red Hat
pypdf: pypdf: Denial of Service via crafted PDF↗2026-02-26
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Debian
CVE-2026-27888: pypdf - pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an atta...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-27888 Impact, Exploitability, and Mitigation Steps | Wiz↗
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