---
id: CVE-2026-112300
title: DiffSK configobj __init__.py _sectionmarker redos
summary: >-
  A vulnerability was identified in DiffSK configobj up to 5.0.9. Affected by
  this vulnerability is the function _sectionmarker of the file
  configobj/__init__.py. The manipulation leads to inefficient regular
  expression complexity. Remote …
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:C'
cvssSource: cna
cwe:
  - CWE-1333
  - CWE-400
vendor: DiffSK
product: configobj
affected:
  - configobj 5.0.0
  - configobj 5.0.1
  - configobj 5.0.2
  - configobj 5.0.3
  - configobj 5.0.4
  - configobj 5.0.5
  - configobj 5.0.6
  - configobj 5.0.7
  - configobj 5.0.8
  - configobj 5.0.9
published: '2026-10-19'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T20:30:18.020Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-112300'
references:
  - url: 'https://vuldb.com/vuln/422346'
    label: VDB-422346 | DiffSK configobj __init__.py _sectionmarker redos
  - url: 'https://vuldb.com/vuln/422346/cti'
    label: 'VDB-422346 | CTI Indicators (IOB, IOC, TTP, IOA)'
  - url: 'https://vuldb.com/cve/CVE-2026-112300'
    label: CVE-2026-112300 | CVE Analysis and Report
  - url: 'https://vuldb.com/submit/989395'
    label: 'Submit #989395 | DiffSK configobj 5.0.9 Denial of Service'
  - url: 'https://github.com/DiffSK/configobj/issues/281'
  - url: 'https://github.com/DiffSK/configobj/'
tags:
  - cve.org
ingestedAt: '2026-10-19T21:43:56.164Z'
---

## Overview

A vulnerability was identified in DiffSK configobj up to 5.0.9. Affected by this vulnerability is the function _sectionmarker of the file configobj/__init__.py. The manipulation leads to inefficient regular expression complexity. Remote exploitation of the attack is possible. The project was informed of the problem early through an issue report but has not responded yet.

## Affected

- `configobj 5.0.0`
- `configobj 5.0.1`
- `configobj 5.0.2`
- `configobj 5.0.3`
- `configobj 5.0.4`
- `configobj 5.0.5`
- `configobj 5.0.6`
- `configobj 5.0.7`
- `configobj 5.0.8`
- `configobj 5.0.9`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.