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
Elevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.1Exploit: Elevated riskExposed services: Not assessed

A fixed version is listed under Patch Availability — apply it.

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
6.1MEDIUMmedium confidence
EG Risk
43
EG Risk 43/100

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%
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

Published

July 6, 2026

Last Modified

July 7, 2026

Advisory Details (3)

Auto-updated Jul 7, 2026
Fixed version listed under Patch Availability.
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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
showdown—
  • every version through 2.1.0: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× 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.

Showing the most recent 100 of 189 total refreshes for this CVE.

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

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 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 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59711?
CVE-2026-59711 has a CVSS base score of 6.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-59711?
A fixed version for CVE-2026-59711 is listed under Patch Availability on this page: update to the version listed for your package. The vendor advisories EchelonGraph has for CVE-2026-59711 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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