CVE-2026-86432

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-09-07. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

September 7, 2026

Last Modified

September 10, 2026

Advisory Details (2)

Auto-updated Sep 7, 2026
Patch available. Sources: github.
generic

commonmark 2.0.0 before 2.8.4 Denial of Service via XML | Advisories | VulnCheck

https://www.vulncheck.com/advisories/commonmark-2.0.0-before-2.8.4-denial-of-service-via-xml
github Patch Available

Denial of service via deeply nested XML output · Advisory · thephpleague/commonmark · GitHub

https://github.com/thephpleague/commonmark/security/advisories/GHSA-mj63-m3rc-8ppr

Vendor Advisories for CVE-2026-86432(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark2.10.0-1 ... 2.9.0-1 (23 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark2.10.0-1 ... 2.9.0-1 (11 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark2.7.0-1 ... 2.8.3-1 (8 versions)2.9.0-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 36× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 01:52 UTCEG score recompute
  2. 2026-09-19 01:52 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 00:42 UTCEG score recompute
  5. 2026-09-18 00:42 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-16 23:32 UTCEG score recompute
  8. 2026-09-16 23:32 UTCGHSA enrichment
  9. 2026-09-16 14:09 UTCEPSS rescore
  10. 2026-09-16 05:15 UTCEPSS rescore
  11. 2026-09-15 22:22 UTCEG score recompute
  12. 2026-09-15 22:21 UTCGHSA enrichment
  13. 2026-09-15 03:12 UTCEPSS rescore
  14. 2026-09-15 03:12 UTCEPSS rescore
  15. 2026-09-14 21:11 UTCGHSA enrichment
  16. 2026-09-13 19:54 UTCEG score recompute
  17. 2026-09-13 19:54 UTCGHSA enrichment
  18. 2026-09-12 18:44 UTCEG score recompute
  19. 2026-09-12 18:44 UTCGHSA enrichment
  20. 2026-09-11 17:34 UTCEG score recompute
  21. 2026-09-11 17:34 UTCGHSA enrichment
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-10 16:24 UTCEG score recompute
  25. 2026-09-10 16:24 UTCGHSA enrichment
Show 11 more
  1. 2026-09-10 15:27 UTCEG score recompute
  2. 2026-09-10 15:27 UTCGHSA enrichment
  3. 2026-09-09 23:18 UTCEG score recompute
  4. 2026-09-09 23:18 UTCGHSA enrichment
  5. 2026-09-08 22:01 UTCEPSS rescore
  6. 2026-09-08 20:13 UTCGHSA enrichment
  7. 2026-09-08 16:15 UTCEG score recompute
  8. 2026-09-08 16:15 UTCGHSA enrichment
  9. 2026-09-07 13:28 UTCEG score recompute
  10. 2026-09-07 12:57 UTCEG score recompute
  11. 2026-09-07 12:56 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-86432?
CVE-2026-86432 is a medium vulnerability published on September 7, 2026. 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…
When was CVE-2026-86432 disclosed?
CVE-2026-86432 was first published in the National Vulnerability Database on September 7, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86432 actively exploited?
CVE-2026-86432 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 83.7% of all scored CVEs.
What is the CVSS score of CVE-2026-86432?
CVE-2026-86432 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-86432?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86432, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-86432

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