CVE-2026-48156

low

Published 2026-05-28 · Modified 2026-05-30

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CVSS v3

3.3

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

CVSS v4 NEW

5.1

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

VIR risk

3.3

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.

Predictions

Exploit likelihood

34%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

Mitigation details

Source: Debian Security Tracker · View original ↗ · DFSG

CVE-2026-48156 NameCVE-2026-48156 Descriptionpypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0. SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS,…

CVE-2026-48156

Name	CVE-2026-48156
Description	pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1138193

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pypdf (PTS)	bookworm	3.4.1-1+deb12u1	vulnerable
	trixie	5.4.0-1	vulnerable
	forky, sid	6.9.2-1	vulnerable
pypdf2 (PTS)	bullseye	1.26.0-4+deb11u1	vulnerable
	bookworm	2.12.1-3+deb12u1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
pypdf	source	(unstable)	(unfixed)			1138193
pypdf2	source	(unstable)	(unfixed)

Notes

https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6
https://github.com/py-pdf/pypdf/pull/3791

Home - Debian Security - Source (Git)

Apply commands

text fix

Notes

https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6https://github.com/py-pdf/pypdf/pull/3791

OS impact

Debian Affected 5 releases

Version	Status	Fixed in
trixie	Affected	—
sid	Affected	—
forky	Affected	—
bullseye	Affected	—
bookworm	Affected	—

Application impact

Vendor	Product	Versions	Fixed
pypdf_project	pypdf	`{"endExcluding":"6.12.0"}`	`6.12.0`

References

CWEs

CWE-834

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.