# CVE-2026-86432

## Summary

- **CVE ID:** CVE-2026-86432
- **Severity:** MEDIUM
- **CVSS Score:** 6.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N)
- **CWE:** CWE-405
- **Published:** Sep 7, 2026
- **Last Modified:** Sep 7, 2026

## Description

commonmark versions from 2.0.0 before 2.8.4 contain a denial of service vulnerability in XmlRenderer that emits depth-proportional indentation for every XML tag. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausting server resources.

## Affected Products

- thephpleague — commonmark (2.8.4)
- thephpleague — commonmark (2.0.0)

## References

- [CNA](https://github.com/thephpleague/commonmark/security/advisories/GHSA-mj63-m3rc-8ppr)
- [CNA](https://www.vulncheck.com/advisories/commonmark-2.0.0-before-2.8.4-denial-of-service-via-xml)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.25%
- **EPSS Percentile:** 16.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._