CVE-2026-54570

MEDIUMPre-NVD 6.96.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 84% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
6.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.9Exploit: Elevated riskExposed: 0

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

AngleSharp is a .NET library for parsing angle bracket based hyper-texts. Prior to 1.5.0, MathAnnotationXmlElement in AngleSharp/Mathml/Dom/Internal/MathAnnotationXmlElement.cs is not treated as an HTML integration point when its encoding attribute is text/html or application/xhtml+xml, causing Consume in AngleSharp/Html/Parser/HtmlDomBuilder.cs to route tokens through foreign-content parsing instead of HTML parsing. A sanitizer can therefore observe a different DOM from the browser that reparses the serialized output. An attacker can combine this namespace differential with markup-breaking characters in an attribute value so that an element hidden from the sanitizer becomes active script-capable HTML after browser reparse, resulting in mutation cross-site scripting. This issue is fixed in version 1.5.0.

CVSS v3
6.9
EG Score
6.9(medium)
EG Risk
47(Track)
EG Risk 47/100SSVC: 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
Severity69% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

July 17, 2026

Last Modified

August 18, 2026

Advisory Details (3)

Auto-updated Aug 18, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

1.5.0

Patch available: AngleSharp/AngleSharp 1.5.0

https://github.com/AngleSharp/AngleSharp/releases/tag/1.5.0
github_commit Patch Available

commit 8033a5c690af (AngleSharp/AngleSharp)

Patch available: AngleSharp/AngleSharp 1.5.0 (contains commit 8033a5c690af)

https://github.com/AngleSharp/AngleSharp/commit/8033a5c690af9c2c443f58e34875343fa4cc1d07
github Patch Available🟡 PoC Available

HTML5 Spec Compliance: mXSS via annotation-xml HTML Integration Point Bypass · Advisory · AngleSharp/AngleSharp · GitHub

https://github.com/AngleSharp/AngleSharp/security/advisories/GHSA-pgww-w46g-26qg

Vendor Advisories for CVE-2026-54570(1)

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

Affected Packages

(1 across 1 ecosystem)
NuGet(1)
PackageVulnerable rangeFixed inDependents
AngleSharp0.10.0 ... 1.4.0 (239 versions)1.5.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 33× 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. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 09:35 UTCEPSS rescore
  3. 2026-09-08 22:01 UTCEPSS rescore
  4. 2026-09-07 23:59 UTCEG score recompute
  5. 2026-09-07 16:01 UTCEPSS rescore
  6. 2026-09-06 13:47 UTCEPSS rescore
  7. 2026-09-05 20:25 UTCEG score recompute
  8. 2026-09-04 05:06 UTCEPSS rescore
  9. 2026-09-02 14:12 UTCEPSS rescore
  10. 2026-09-01 13:54 UTCEPSS rescore
  11. 2026-09-01 04:40 UTCEPSS rescore
  12. 2026-08-31 05:14 UTCEG score recompute
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 03:14 UTCEG score recompute
  15. 2026-08-30 01:22 UTCEPSS rescore
  16. 2026-08-28 21:41 UTCEPSS rescore
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-27 13:51 UTCEG score recompute
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-26 11:55 UTCEG score recompute
  21. 2026-08-25 13:49 UTCEPSS rescore
  22. 2026-08-25 09:47 UTCEG score recompute
  23. 2026-08-23 05:15 UTCEG score recompute
  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-22 03:18 UTCEG score recompute
Show 12 more
  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-21 01:21 UTCEG score recompute
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-19 23:25 UTCEG score recompute
  5. 2026-08-19 17:04 UTCEPSS rescore
  6. 2026-08-18 20:24 UTCEG score recompute
  7. 2026-08-18 19:30 UTCEG score recompute
  8. 2026-08-18 18:25 UTCEG score recompute
  9. 2026-07-30 19:08 UTCEG score recompute
  10. 2026-07-26 11:17 UTCEG score recompute
  11. 2026-07-23 03:19 UTCEG score recompute
  12. 2026-07-17 22:00 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54570?
CVE-2026-54570 is a medium vulnerability published on July 17, 2026. AngleSharp is a .NET library for parsing angle bracket based hyper-texts. Prior to 1.5.0, MathAnnotationXmlElement in AngleSharp/Mathml/Dom/Internal/MathAnnotationXmlElement.cs is not treated as an HTML integration point when its encoding attribute is text/html or application/xhtml+xml, causing…
When was CVE-2026-54570 disclosed?
CVE-2026-54570 was first published in the National Vulnerability Database on July 17, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54570 actively exploited?
CVE-2026-54570 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 84.1% of all scored CVEs.
What is the CVSS score of CVE-2026-54570?
CVE-2026-54570 has a CVSS v3 base score of 6.9 (NVD).
How do I remediate CVE-2026-54570?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54570, 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-2026-54570

Explore →

Is Your Infrastructure Affected by CVE-2026-54570?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs