Improper Restriction of XML External Entity Reference in pikepdf

published 2021-04-01 5 y ago modified 2026-09-10 1 mo ago also GHSA-ccgm-3xw4-h5p8 , PYSEC-2021-34 , EUVD-2021-0166

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.7%; EPSS 1.7% chance of exploitation in 30 days, percentile 77%
public exploits: 0; none known

models/metadata.py in the pikepdf package 1.3.0 through 2.9.2 for Python allows XXE when parsing XMP metadata entries.

Patch / fix

fixed in 1 distros 4 links 1

pypi pikepdf 2.10.0

debian opensuse alpine arch linux

pikepdf Debian 14, Debian 13, Debian 12 1.17.3+dfsg-5

debian advisories DEBIAN-CVE-2021-29421

python-pikepdf openSUSE Tumbleweed 10.5.1-2.1

opensuse advisories openSUSE-SU-2026:11355-1

py3-pikepdf Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 2.9.1-r2

alpine advisories ALPINE-CVE-2021-29421

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

python-pikepdf Arch Linux 2.10.0-1

arch linux advisories AVG-1761

github.com/pikepdf/pikepdf@3f38f73 commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-29421 updated 2025-11-21 cvss 7.5

pikepdf: XML external entity issue when parsing XMP metadata entries

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.68% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:P/I:N/A:N
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	pikepdf	>=1.3.0, <2.10.0	2.10.0

Classification

Weakness

CWE-611 Improper Restriction of XML External Entity Reference

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary