CVE-2026-54651: py-pdf pypdf Infinite Loop
CVSS: 6.9v4.0MediumAnalyzed
AliasesGHSA-g9xf-7f8q-9mcjPYSEC-2026-3018UBUNTU-CVE-2026-54651DEBIAN-CVE-2026-54651openSUSE-SU-2026:11113-1
Published 22-06-2026Last modified 23-06-2026
Vulnerability summary
CVE-2026-54651 is a medium (CVSS 6.9) Infinite Loop vulnerability in py-pdf pypdf. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.5% of scored vulnerabilities.
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)EPSS score
0.16%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 22-06-2026PublishedVulnerability first disclosed.
- 23-06-2026Last modifiedVulnerability information updated.
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.13.1, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with threads/articles into a writer. This vulnerability is fixed in 6.13.1.
CVSS metrics
7 scores · 5 sources · 2 versionsMedium 6.9Preferred score · CVE.org (CNA)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NSourcesAll 4 agree
- OSV · PypiEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · UbuntuEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- NVDNIST6.9MediumCVSS: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
Medium 5.5Preferred score · OSV · Ubuntu (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HSourcesAll 3 agree
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.16%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
0.00 pp
From 0.16% on 19-09-2026
19-09-202619-10-2026
EPSS score0.16%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu3 products
- pypdfAll versions (No fix recorded)
- pypdf2All versions (No fix recorded)
- python-pypdfAll versions (No fix recorded)
Debian2 products
- pypdfAll versions (No fix recorded) | < 6.19.0-1
- pypdf2All versions (No fix recorded)
Opensuse1 product
- python-pypdf&distro=openSUSE Tumbleweed< 6.14.0-1.1
Py-pdf1 product
- pypdf< 6.13.1
Pypdf_project1 product
- pypdf< 6.13.1
PyPI1 product
- pypdf< 6.13.1
6 vendors · 9 products
References
11 links- github.com/py-pdf/pypdf/security/advisories/GHSA-g9xf-7f8q-9mcjX Refsource CONFIRMWEBREPORTMitigationPatchVendor Advisory
- github.com/py-pdf/pypdfPACKAGE
- pypi.org/project/pypdfPACKAGE
