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MEDIUM severity

CVE-2023-26112 — configobj

MEDIUMFix: DiffSK/configobj@7c618b0

CVE-2023-26112 is a medium-severity (CVSS 5.9) CWE-1333 vulnerability in configobj. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for configobj — see the affected versions and patch details below.

configobj ReDoS exploitable by developer using values in a server-side configuration file

Also known asGHSA-c33w-24p9-8m24PYSEC-2026-1270
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-26112.

EPSS Exploitation Probability

via FIRST.org ↗
1.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs70th percentile — riskier than 70% of all scored CVEsHighest risk
0.00%0.59%1.18%1.77%0.1%1.3%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐍configobj

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

All versions of the package configobj are vulnerable to Regular Expression Denial of Service (ReDoS) via the validate function, using (.+?)((.*)).

Note: This is only exploitable in the case of a developer, putting the offending value in a server side configuration file.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIconfigobjall versions5.0.9pip install --upgrade 'configobj==5.0.9'

Affected Products

1 product · 1 configurations
Application
configobjconfigobj_project
all
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

All versions of the package configobj are vulnerable to Regular Expressi…

security.snyk.ioNVDApr 2023

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for configobj, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update configobj to 5.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26112 is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

All versions of the package configobj are vulnerable to Regular Expression Denial of Service (ReDoS) via the validate function, using (.+?)\((.*)\). **Note:** This is only exploitable in the case of a developer, putting the offending value in a server side configuration file.
O3 Security · Impact-Aware SCA

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CVE-2023-26112: configobj DoS — Fixed in 5.0.9