CVE-2026-59711

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

Score 6.1 from GitHub Security Advisory published 2026-07-06. a secondary CVSS source baseline 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: Elevated riskExposed: 0

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

showdown contains a cross-site scripting vulnerability in metadata title handling that allows attackers to inject arbitrary HTML and JavaScript. When completeHTMLDocument option is enabled, unescaped less-than and greater-than characters in markdown frontmatter metadata are inserted directly into HTML title tags, enabling attackers to break out of the title context and execute malicious scripts in the rendered page.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

July 6, 2026

Last Modified

July 7, 2026

Advisory Details (3)

Auto-updated Jul 7, 2026
No patch confirmed yet.
generic

showdown - Cross-Site Scripting via Unescaped Metadata Title in completeHTMLDocument | Advisories | VulnCheck

https://www.vulncheck.com/advisories/showdown-cross-site-scripting-via-unescaped-metadata-title-in-completehtmldocument
generic

GitHub - showdownjs/showdown: A bidirectional Markdown to HTML to Markdown converter written in Javascript · GitHub

https://github.com/showdownjs/showdown
generic

XSS via Metadata Title Injection (completeHTMLDocument) · Issue #1047 · showdownjs/showdown · GitHub

https://github.com/showdownjs/showdown/issues/1047

Vendor Advisories for CVE-2026-59711(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
npmshowdown—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
showdown———

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 84× 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.

Showing the most recent 100 of 132 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 03:29 UTCEG score recompute
  3. 2026-08-25 03:29 UTCGHSA enrichment
  4. 2026-08-24 04:05 UTCGHSA enrichment
  5. 2026-08-23 04:11 UTCEG score recompute
  6. 2026-08-23 04:11 UTCGHSA enrichment
  7. 2026-08-23 00:19 UTCEPSS rescore
  8. 2026-08-22 04:47 UTCEG score recompute
  9. 2026-08-22 04:47 UTCGHSA enrichment
  10. 2026-08-21 23:49 UTCEPSS rescore
  11. 2026-08-21 04:15 UTCEG score recompute
  12. 2026-08-21 04:15 UTCGHSA enrichment
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-20 03:39 UTCEG score recompute
  15. 2026-08-20 03:39 UTCGHSA enrichment
  16. 2026-08-19 17:04 UTCEPSS rescore
  17. 2026-08-19 03:55 UTCEG score recompute
  18. 2026-08-19 03:55 UTCGHSA enrichment
  19. 2026-08-18 13:48 UTCEPSS rescore
  20. 2026-08-18 03:05 UTCEG score recompute
  21. 2026-08-18 03:04 UTCGHSA enrichment
  22. 2026-08-17 13:47 UTCEPSS rescore
  23. 2026-08-17 01:05 UTCEG score recompute
  24. 2026-08-17 01:05 UTCGHSA enrichment
  25. 2026-08-16 14:56 UTCEPSS rescore
Show 75 more
  1. 2026-08-16 02:14 UTCEPSS rescore
  2. 2026-08-16 01:41 UTCGHSA enrichment
  3. 2026-08-15 02:17 UTCEG score recompute
  4. 2026-08-15 02:17 UTCGHSA enrichment
  5. 2026-08-15 01:30 UTCEPSS rescore
  6. 2026-08-14 02:53 UTCEG score recompute
  7. 2026-08-14 02:53 UTCGHSA enrichment
  8. 2026-08-13 22:00 UTCEPSS rescore
  9. 2026-08-13 03:30 UTCEG score recompute
  10. 2026-08-13 03:30 UTCGHSA enrichment
  11. 2026-08-12 13:51 UTCEPSS rescore
  12. 2026-08-12 04:06 UTCEG score recompute
  13. 2026-08-12 04:06 UTCGHSA enrichment
  14. 2026-08-11 04:42 UTCEG score recompute
  15. 2026-08-11 04:42 UTCGHSA enrichment
  16. 2026-08-11 00:00 UTCEPSS rescore
  17. 2026-08-10 05:18 UTCEG score recompute
  18. 2026-08-10 05:18 UTCGHSA enrichment
  19. 2026-08-09 13:46 UTCEPSS rescore
  20. 2026-08-09 05:55 UTCEG score recompute
  21. 2026-08-09 05:55 UTCGHSA enrichment
  22. 2026-08-08 16:37 UTCEPSS rescore
  23. 2026-08-08 06:31 UTCEG score recompute
  24. 2026-08-08 06:31 UTCGHSA enrichment
  25. 2026-08-07 07:07 UTCEG score recompute
  26. 2026-08-07 07:07 UTCGHSA enrichment
  27. 2026-08-06 13:47 UTCEPSS rescore
  28. 2026-08-06 07:43 UTCEG score recompute
  29. 2026-08-06 07:43 UTCGHSA enrichment
  30. 2026-08-05 19:17 UTCEPSS rescore
  31. 2026-08-05 08:20 UTCEG score recompute
  32. 2026-08-05 08:20 UTCGHSA enrichment
  33. 2026-08-04 15:10 UTCEPSS rescore
  34. 2026-08-04 10:39 UTCEPSS rescore
  35. 2026-08-04 08:55 UTCEG score recompute
  36. 2026-08-04 08:55 UTCGHSA enrichment
  37. 2026-08-03 10:36 UTCEPSS rescore
  38. 2026-08-03 09:30 UTCGHSA enrichment
  39. 2026-08-02 10:02 UTCEG score recompute
  40. 2026-08-02 10:02 UTCGHSA enrichment
  41. 2026-08-02 02:27 UTCEPSS rescore
  42. 2026-08-01 10:39 UTCEG score recompute
  43. 2026-08-01 10:39 UTCGHSA enrichment
  44. 2026-08-01 04:16 UTCEPSS rescore
  45. 2026-07-31 11:10 UTCEG score recompute
  46. 2026-07-31 11:10 UTCGHSA enrichment
  47. 2026-07-30 16:28 UTCEPSS rescore
  48. 2026-07-30 11:29 UTCEG score recompute
  49. 2026-07-30 11:29 UTCGHSA enrichment
  50. 2026-07-30 01:30 UTCEPSS rescore
  51. 2026-07-30 01:30 UTCEPSS rescore
  52. 2026-07-29 12:05 UTCEG score recompute
  53. 2026-07-29 12:05 UTCGHSA enrichment
  54. 2026-07-28 15:37 UTCEPSS rescore
  55. 2026-07-28 12:41 UTCEG score recompute
  56. 2026-07-28 12:40 UTCGHSA enrichment
  57. 2026-07-27 14:14 UTCEPSS rescore
  58. 2026-07-27 12:10 UTCEG score recompute
  59. 2026-07-27 12:10 UTCGHSA enrichment
  60. 2026-07-26 14:54 UTCEPSS rescore
  61. 2026-07-26 14:54 UTCEPSS rescore
  62. 2026-07-26 12:46 UTCEG score recompute
  63. 2026-07-26 12:46 UTCGHSA enrichment
  64. 2026-07-25 14:18 UTCEPSS rescore
  65. 2026-07-25 14:18 UTCEPSS rescore
  66. 2026-07-24 14:18 UTCEPSS rescore
  67. 2026-07-24 14:18 UTCEPSS rescore
  68. 2026-07-23 14:18 UTCEPSS rescore
  69. 2026-07-23 14:18 UTCEPSS rescore
  70. 2026-07-23 03:21 UTCEG score recompute
  71. 2026-07-22 14:08 UTCEPSS rescore
  72. 2026-07-22 14:08 UTCEPSS rescore
  73. 2026-07-21 15:25 UTCEPSS rescore
  74. 2026-07-21 15:25 UTCEPSS rescore
  75. 2026-07-20 17:08 UTCEPSS rescore

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-59711?
CVE-2026-59711 is a medium vulnerability published on July 6, 2026. showdown contains a cross-site scripting vulnerability in metadata title handling that allows attackers to inject arbitrary HTML and JavaScript. When completeHTMLDocument option is enabled, unescaped less-than and greater-than characters in markdown frontmatter metadata are inserted directly into…
When was CVE-2026-59711 disclosed?
CVE-2026-59711 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on July 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59711 actively exploited?
CVE-2026-59711 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 75.0% of all scored CVEs.
What is the CVSS score of CVE-2026-59711?
CVE-2026-59711 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-59711?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59711, 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-2026-59711

Explore →

Is Your Infrastructure Affected by CVE-2026-59711?

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

Start Free Scan →Browse All CVEs