CVE-2023-42821

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 35% 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, nvd
Elevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

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

The package github.com/gomarkdown/markdown is a Go library for parsing Markdown text and rendering as HTML. Prior to pseudoversion 0.0.0-20230922105210-14b16010c2ee, which corresponds with commit 14b16010c2ee7ff33a940a541d993bd043a88940, parsing malformed markdown input with parser that uses parser.Mmark extension could result in out-of-bounds read vulnerability. To exploit the vulnerability, parser needs to have parser.Mmark extension set. The panic occurs inside the citation.go file on the line 69 when the parser tries to access the element past its length. This can result in a denial of service. Commit 14b16010c2ee7ff33a940a541d993bd043a88940/pseudoversion 0.0.0-20230922105210-14b16010c2ee contains a patch for this issue.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
60.5%
KEV
Not listed

Published

September 22, 2023

Last Modified

June 17, 2026

References (6)

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/gomarkdown/markdown—0.0.0-20230922105210-14b16010c2ee—

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 10× in last 7d / 47× 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 107 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2023-42821?
CVE-2023-42821 is a high vulnerability published on September 22, 2023. The package github.com/gomarkdown/markdown is a Go library for parsing Markdown text and rendering as HTML. Prior to pseudoversion 0.0.0-20230922105210-14b16010c2ee, which corresponds with commit 14b16010c2ee7ff33a940a541d993bd043a88940, parsing malformed markdown input with parser that uses…
When was CVE-2023-42821 disclosed?
CVE-2023-42821 was first published in the National Vulnerability Database on September 22, 2023, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-42821 actively exploited?
CVE-2023-42821 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 60.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2023-42821?
CVE-2023-42821 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2023-42821?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-42821, 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

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