How severe is CVE-2023-3431?

CVE-2023-3431 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-3431?

CVE-2023-3431 affects the following packages: net.sourceforge.plantuml:plantuml-mit (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-3431?

Update net.sourceforge.plantuml:plantuml-mit to 1.2023.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-3431 is resolved across your whole dependency graph.

How do I detect CVE-2023-3431 in my Maven dependencies?

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

How do I mitigate CVE-2023-3431 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2023-3431 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-3431, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-3431?

CVE-2023-3431 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 59th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-3431?

CVE-2023-3431 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-3431 published, and has it been updated?

CVE-2023-3431 was published on June 27, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2023-3431 — plantuml-mit

MEDIUMFix: plantuml/plantuml@fbe7fa3

CVE-2023-3431 is a medium-severity (CVSS 5.3) CWE-284 vulnerability in net.sourceforge.plantuml:plantuml-mit. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for net.sourceforge.plantuml:plantuml-mit — see the affected versions and patch details below.

Improper Access Control in plantuml/plantuml

Also known asGHSA-p2mf-q26j-3xmh

Published

Jun 27, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs59th percentile — riskier than 59% of all scored CVEsHighest risk

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

☕net.sourceforge.plantuml:plantuml-mit

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

Description

Improper Access Control in GitHub repository plantuml/plantuml prior to 1.2023.9.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`net.sourceforge.plantuml:plantuml-mit`	all versions	1.2023.9`net.sourceforge.plantuml:plantuml-mit:1.2023.9`

Affected Products

2 products · 2 configurations

fedorafedoraproject

1 version

Application

plantumlplantuml

< 1.2023.9

range

Exploits & PoCs

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

Improper Access Control in GitHub repository plantuml/plantuml prior to …

huntr.devNVDJul 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net.sourceforge.plantuml:plantuml-mit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update net.sourceforge.plantuml:plantuml-mit to 1.2023.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-3431 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

Improper Access Control in GitHub repository plantuml/plantuml prior to 1.2023.9.

O3 Security · Impact-Aware SCA

Is CVE-2023-3431 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Raw vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CWE Classification

CWE-284CWE-284

Weaponization

No Nuclei template or Metasploit module yet. 1 public proof-of-concept reference is listed on this page.

Timeline

Disclosed

Jun 27, 2023

First exploit

Jul 3, 2023

6 days after disclosure — rapid exploitation

Last updated

Oct 28, 2026

Identifiers

CVE-2023-3431

GHSA-p2mf-q26j-3xmh

References

Advisorygithub.com · CVE 2023 3431.json Advisorynvd.nist.gov · CVE 2023 3431 Fixgithub.com · fbe7fa3b25b4c887d83927cffb1009ec6cb8ab1e Webhuntr.dev · fa741f95 b53c 4ed7 b157 e32c5145164c Weblists.fedoraproject.org · FV7XL3CY3K3K5ER3ASMEQA546MIQQ7QM Weblists.fedoraproject.org · FV7XL3CY3K3K5ER3ASMEQA546MIQQ7QM Packagegithub.com · plantuml

Related vulnerabilities

Also affects plantuml-mit

This CVE is medium severity; 1 of 1 other CVE affecting plantuml-mit is rated as high or higher (top: high).

CVE-2023-3432

Same weakness: CWE-284

This CVE is medium severity; 7 of 7 other CVEs with CWE-284 are rated as high or higher (top: high).

GHSA-7mr3-28h5-m5vxCVE-2026-16454GHSA-qx75-2p3r-pwm5CVE-2026-118662CVE-2026-27975CVE-2026-62197CVE-2026-112946Browse all CWE-284

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 28, 2026

CVE-2023-3431 — plantuml-mit

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2023-3431 in your dependencies?