CVE-2026-84309

mediumpriority · track · 22EPSS 0.002 · 8 %ileRUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.19% (8th) EPSS
CVSS 5.5 · medium
Is it mine?
3 products
Check your exposure
Who says so?
3 sources
fstec_bdu · osv · nvd

EPSS · scored 2026-10-28

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.0, an attacker can craft a PDF whose cyclic tree structure causes pypdf/generic/_data_structures.py TreeObject.insert_child to follow /Next links indefinitely when a writing code path inserts a child, producing an infinite loop. This issue is fixed in version 6.16.0.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–7.5

v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 3.6
v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v4.06.9mediumCVSS: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:Xsecondary · security-advisories@github.com
v4.04.6mediumCVSS: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:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-835USCWE-835USCWE-835US
04

affected products (3)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • GHSA-jp53-mhqp-8xcgpypdf: Possible infinite loop for TreeObject.insert_child2026-09-01ghsa · osvUS

    ### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires a (usually writing) code path where `TreeObject.insert_child` is involved. ### Patches This has been fixed in [pypdf==6.16.0](https://github.com/py-pdf/pypdf/releases/tag/6.16.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3964](https://github.com/py-pdf/pypdf/pull/3964).

  • PYSEC-2026-3913pypdf: Possible infinite loop for TreeObject.insert_child2026-09-10vendor · osvUS

    ### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires a (usually writing) code path where `TreeObject.insert_child` is involved. ### Patches This has been fixed in [pypdf==6.16.0](https://github.com/py-pdf/pypdf/releases/tag/6.16.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3964](https://github.com/py-pdf/pypdf/pull/3964).

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

fstec_bduosvnvdNVDCVE.orgMITRE
published 2026-09-01modified 2026-09-02
08

references (4) nvd

External citations — patches, advisories, analysis.

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