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 51% 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

A fix is available — apply it.

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
49%
KEV
Not listed

Published

June 24, 2026

Last Modified

August 28, 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(3)

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
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17870735932026-08-27redhat

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

(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 11× in last 7d / 50× 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 207 total refreshes for this CVE.

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

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 August 28, 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 51.3% 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

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