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GHSA-jp53-mhqp-8xcg CVE-2026-84309 PYSEC-2026-3913

pypdf: Possible infinite loop for TreeObject.insert_child

Medium PyPI
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.19%
Chance of exploitation in the next 30 days. Higher than 8.31% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
Fix
6.16.0
Upgrade pypdf to this version or later

Description

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.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #3964.

Affected versions

PyPI

PackageVulnerableFixed in
pypdf
< 6.16.0
6.16.0

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

pypdf PyPI → 6.16.0

pip
pip install --upgrade "pypdf>=6.16.0"
poetry
poetry add "pypdf>=6.16.0"
uv
uv add "pypdf>=6.16.0"

Severity breakdown

CVSS 4.0 0.0

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

Attack vector
Local
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 5.5

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

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Weakness

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-5849-834g-hvw5
pypdf has possible infinite loop when hitting EOF in standard xref table during trailer search
High Also affects pypdf
GHSA-cggf-277g-3q54
pypdf has possible large memory usage when parsing page tree
High Also affects pypdf
GHSA-mfr5-77xh-9j7h
pypdf has possible infinite loop when cloning dictionaries
High Also affects pypdf
GHSA-42gh-23hr-vphw
pypdf has possible long runtimes when retrieving page labels
High Also affects pypdf
GHSA-4vqv-7265-gm2w
pypdf has possible large memory usage for exceptions in strict mode
High Also affects pypdf
GHSA-62m5-6wh8-28x7
pypdf has possible long runtimes/large memory usage for encrypted PDF files
High Also affects pypdf
GHSA-x3rh-gjgm-fmqc
pypdf has possible large memory usage when parsing cross-reference streams
High Also affects pypdf
GHSA-jr96-gvgh-j3r4
pypdf: Possible long runtimes for repeated malformed cross-reference entries (Follow-up)
High Also affects pypdf
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