CVE-2026-84311: py-pdf pypdf Excessive Iteration
Vulnerability summary
CVE-2026-84311 is a medium (CVSS 4.8) Excessive Iteration vulnerability in py-pdf pypdf. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 2.6% of scored vulnerabilities.
Timeline
- 01-09-2026PublishedVulnerability first disclosed.
- 02-09-2026Last modifiedVulnerability information updated.
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.
CVSS metrics
9 scores · 7 sources · 2 versions- OSV · PypiEcosystem advisory · calculated4.8MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · UbuntuEcosystem advisory · calculated4.8MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · WolfiEcosystem advisory · calculated4.8MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated4.8MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- NVDNIST4.8MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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
- OSV · DebianEcosystem advisory · calculated3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- NVDNIST3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS trend
Probability
0.14%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
0.00 pp
From 0.14% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- pypdfAll versions (No fix recorded) | < 6.19.0-1
- pypdf2All versions (No fix recorded)
Ubuntu2 products
- pypdfAll versions (No fix recorded)
- pypdf2All versions (No fix recorded)
Chainguard1 product
- open-webui< 0.11.3-r4
Py-pdf1 product
- pypdf< 6.16.1
Pypdf_project1 product
- pypdf< 6.16.1
PyPI1 product
- pypdf< 6.16.1
Wolfi1 product
- open-webui< 0.11.3-r4
7 vendors · 9 products
References
13 links- github.com/py-pdf/pypdf/security/advisories/GHSA-763m-79hh-57f2X Refsource CONFIRMWEBAdvisoryPatchVendor Advisory
- github.com/py-pdf/pypdfPACKAGE
- pypi.org/project/pypdfPACKAGE
