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
26%
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 12× in last 7d / 49× 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 168 total refreshes for this CVE.

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

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 74.0% 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

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