Every CVE Search/ Get API key

CVE-2026-54531

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

6.9 MediumFix available

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Attack profile

How easy it is to exploit

Attack vector
Local
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
High

Exploit likelihood

0.17%Unchanged since Jun 23, 2026
90%50%10%1%

What each source reports

CVE List Score used 6.9

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Record
CVE-2026-54531
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness
CWE-835
Updated
2026-11-02
EUVDEUVD-2026-38355 6.9

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Record
EUVD-2026-38355
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated
2026-11-02
GitHub AdvisoriesGHSA-m2v9-299j-rv96 6.9

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

Impact

An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer.

Patches

This has been fixed in pypdf==6.13.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3830.

Record
GHSA-m2v9-299j-rv96
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness
CWE-835
Updated
2026-11-02
NVD 6.9

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Record
CVE-2026-54531
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-835
Updated
2026-11-02
OSV 6.9

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Record
CVE-2026-54531
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness
CWE-835
Updated
2026-11-04
OSVDEBIAN-CVE-2026-54531 5.5

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Record
DEBIAN-CVE-2026-54531
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-03
Show 5 moreShow less
OSVGHSA-m2v9-299j-rv96 6.9

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

Impact

An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer.

Patches

This has been fixed in pypdf==6.13.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3830.

Record
GHSA-m2v9-299j-rv96
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness
CWE-835
Updated
2026-11-02
OSVPYSEC-2026-3022 6.9

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

Impact

An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer.

Patches

This has been fixed in pypdf==6.13.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3830.

Record
PYSEC-2026-3022
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated
2026-11-02
OSVUBUNTU-CVE-2026-54531 6.9

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. This vulnerability is fixed in 6.13.0.

Record
UBUNTU-CVE-2026-54531
CVSS 4.0
6.9 MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS 3.1
5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVCLSA-2026-1783472549 No score

TuxCare security update for pypdf (2 CVEs)

TuxCare rebuilt pypdf to address 2 CVEs. Fixed in 5.9.0.post10+tuxcare.

Record
CLSA-2026-1783472549
Updated
2026-11-02
OSVROOT-APP-PYPI-CVE-2026-54531 No score

CVE-2026-54531 in pypdf - Patched by Root

Root has patched CVE-2026-54531 in the pypdf package for Root:PyPI. Multiple fixed versions available.

Record
ROOT-APP-PYPI-CVE-2026-54531
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
pypdf
PyPI
 before 6.13.0
6.13.0
pypdf
TuxCare:PyPI
From an advisory covering 2 CVEs
 5.9.0 up to 5.9.0.post10+tuxcare, plus listed versions
5.9.0.post1+tuxcare5.9.0.post2+tuxcare5.9.0.post3+tuxcare5.9.0.post4+tuxcare5.9.0.post5+tuxcare
Show 4 moreShow less
5.9.0.post6+tuxcare5.9.0.post7+tuxcare5.9.0.post8+tuxcare5.9.0.post9+tuxcare
5.9.0.post10+tuxcare
pypdf
Debian:12
 All versions, plus listed versions
3.17.4-13.4.1-13.4.1-1+deb12u14.0.0-14.0.0-1~exp1
Show 13 moreShow less
4.0.1-14.0.2-14.1.0-14.2.0-14.3.1-15.4.0-16.19.0-16.21.0-16.21.1-16.21.4-16.9.0-16.9.2-16.9.2-2
 None known
pypdf
Debian:13
 All versions, plus listed versions
5.4.0-16.19.0-16.21.0-16.21.1-16.21.4-16.9.0-16.9.2-16.9.2-2
 None known
pypdf
Debian:14
 before 6.19.0-1, plus listed versions
5.4.0-16.9.0-16.9.2-16.9.2-2
6.19.0-1
pypdf2
Debian:12
 All versions, plus listed versions
2.12.1-32.12.1-3+deb12u12.12.1-4
 None known
pypdf
PyPI
 before 6.13.0, plus listed versions
1.01.11.101.111.12
Show 45 moreShow less
1.131.21.31.41.51.61.71.81.93.1.03.10.03.11.03.11.13.12.03.12.13.12.23.13.03.14.03.15.03.15.13.15.23.15.33.15.43.15.53.16.03.16.13.16.23.16.33.16.43.17.03.17.13.17.23.17.33.17.43.2.03.2.13.3.03.4.03.4.13.5.03.5.13.5.23.6.03.7.03.7.1
6.13.0
pypdf
Root:PyPI
 before 6.6.0+aikido.10
6.6.0+aikido.106.10.1+aikido.46.10.1+aikido.56.10.2+aikido.16.6.0+aikido.116.11.0+aikido.16.12.0+aikido.16.12.1+aikido.16.12.2+aikido.16.11.0+aikido.26.6.0+aikido.126.10.2+aikido.26.12.1+aikido.26.10.1+aikido.66.12.1+aikido.36.12.0+aikido.26.10.1+aikido.76.12.0+aikido.36.10.2+aikido.36.11.0+aikido.36.12.2+aikido.26.12.1+aikido.46.6.0+aikido.136.12.0+aikido.46.12.2+aikido.36.11.0+aikido.46.12.0+aikido.56.6.0+aikido.146.10.2+aikido.46.12.2+aikido.46.10.1+aikido.86.10.1+aikido.96.6.0+aikido.156.10.1+aikido.106.11.0+aikido.56.12.0+aikido.66.10.2+aikido.56.12.1+aikido.56.12.2+aikido.5
rootio-pypdf
Root:PyPI
 before 6.6.0+root.io.10
6.6.0+root.io.106.10.1+root.io.46.10.1+root.io.56.10.2+root.io.16.6.0+root.io.116.11.0+root.io.16.12.0+root.io.16.12.1+root.io.16.12.2+root.io.16.11.0+root.io.2
pypdf2
Ubuntu:Pro:16.04:LTS
 All versions, plus listed versions
1.23+git20141008-11.25.1-11.25.1-1ubuntu0.1~esm11.25.1-1ubuntu0.1~esm2
 None known
Show 9 moreShow less
Affected packages
PackageAffectedFixed
python-pypdf
Ubuntu:16.04:LTS
 All versions, plus listed versions
1:1.13-3
 None known
pypdf2
Ubuntu:Pro:18.04:LTS
 All versions, plus listed versions
1.26.0-21.26.0-2ubuntu0.1~esm11.26.0-2ubuntu0.1~esm2
 None known
pypdf2
Ubuntu:20.04:LTS
 All versions, plus listed versions
1.26.0-21.26.0-3ubuntu11.26.0-3ubuntu1.20.04.11.26.0-3ubuntu1.20.04.2
 None known
pypdf2
Ubuntu:22.04:LTS
 All versions, plus listed versions
1.26.0-41.26.0-4ubuntu0.22.04.11.26.0-4ubuntu0.22.04.2
 None known
pypdf
Ubuntu:24.04:LTS
 All versions, plus listed versions
3.4.1-13.17.4-14.0.0-14.0.1-14.0.2-1
 None known
pypdf2
Ubuntu:24.04:LTS
 All versions, plus listed versions
2.12.1-32.12.1-4
 None known
pypdf
Ubuntu:25.10
 All versions, plus listed versions
4.3.1-15.4.0-1
 None known
pypdf
Ubuntu:26.10
 All versions, plus listed versions
6.9.2-16.9.2-2
 None known
pypdf
Ubuntu:26.04:LTS
 All versions, plus listed versions
5.4.0-16.9.2-1
 None known

History

History
RecordedChangedSources
affected
factsOSV
affectedOSV
productsNVD
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-54531 is a medium vulnerability (CVSS 6.9) in Py-pdf Pypdf, published June 16, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. Fixed in pypdf 6.13.0.

References

Show 5 moreShow less
This page doesn't list everything

Left out here: 55 versions. The JSON record has them.

Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open