CVE-2026-49851

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 53% 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
Trending — 3 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0

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

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in parse_link_text. When parsing Markdown containing many consecutive [ characters, parse_link_text repeatedly scans the input using a regex search inside a loop. Each iteration re-scans a large portion of the remaining string, resulting in quadratic-time behavior. An attacker-controlled Markdown input can therefore trigger excessive CPU usage with a very small payload. This vulnerability is fixed in 3.3.0.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

June 24, 2026

Last Modified

July 15, 2026

Advisory Details (1)

Auto-updated Jun 24, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Potential DoS via quadratic-time parsing in parse_link_text · Advisory · lepture/mistune · GitHub

https://github.com/lepture/mistune/security/advisories/GHSA-qcq2-496w-v96p

Vendor Advisories for CVE-2026-49851(2)

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

Affected Packages

(3 across 3 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
mistune3.1.3-1, 3.1.4-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
mistune3.1.3-1, 3.1.4-1——
PyPI(1)
PackageVulnerable rangeFixed inDependents
mistune0.1.0 ... 3.2.1 (51 versions)3.3.0—

Weakness Classification(4)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 101× 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 174 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-49851?
CVE-2026-49851 is a high vulnerability published on June 24, 2026. Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in parselinktext. When parsing Markdown containing many consecutive [ characters, parselinktext repeatedly scans the input…
When was CVE-2026-49851 disclosed?
CVE-2026-49851 was first published in the National Vulnerability Database on June 24, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49851 actively exploited?
CVE-2026-49851 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 52.5% of all scored CVEs.
What is the CVSS score of CVE-2026-49851?
CVE-2026-49851 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-49851?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49851, 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-2026-49851

Explore →

Is Your Infrastructure Affected by CVE-2026-49851?

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

Start Free Scan →Browse All CVEs