CVE-2026-59927

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (43rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
5.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, allowing two markdown files that include each other to trigger unbounded recursion, raise RecursionError, and crash the rendering request. This issue is fixed in version 3.3.0.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100

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 (value × EchelonGraph’s weight)
Severity53% × 45%
The EG Score, 5.3 of 10.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
43rd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 8, 2026

Last Modified

July 9, 2026

Advisory Details (3)

Auto-updated Jul 8, 2026
Patch available. Sources: github_commit, github_release, github.
GitHub advisoryMentions a patch (unverified)

directives/include: mutual `.. include::` recursion crashes the renderer with `RecursionError`, denial of service via two attacker-controlled markdown files · Advisory · lepture/mistune · GitHub

https://github.com/lepture/mistune/security/advisories/GHSA-8mpj-m6qm-5qr8
GitHub release Patch Available

v3.3.0

Patch available: lepture/mistune v3.3.0

https://github.com/lepture/mistune/releases/tag/v3.3.0
GitHub commit Patch Available

commit 1bef343ade16 (lepture/mistune)

Patch available: lepture/mistune v3.3.0 (contains commit 1bef343ade16)

https://github.com/lepture/mistune/commit/1bef343ade163fc3bb95572b15be720084cdb993

Vendor Advisories for CVE-2026-59927(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
mistune2.0.4-1 ... 3.3.4-1 (7 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
mistune3.1.3-1, 3.1.4-1, 3.3.4-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
mistune3.1.3-1, 3.1.4-1, 3.3.4-1
  • every version on: no fix on record
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
mistune0.1.0 ... 3.2.1 (51 versions)
  • every version up to 3.3.0: fixed in 3.3.0
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 36× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 139 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 39 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-11 19:36 UTCEG score recompute
  2. 2026-10-11 16:51 UTCEG score recompute
  3. 2026-10-11 14:13 UTCEG score recompute
  4. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  7. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  9. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  10. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  11. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  13. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  14. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  15. 2026-10-01 16:11 UTCEG score recompute
  16. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  18. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  19. 2026-09-28 13:22 UTCEG score recompute
  20. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-09-24 11:48 UTCEG score recompute
  24. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  25. 2026-09-23 06:10 UTCEG score recompute
Show 75 more
  1. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-09-18 05:43 UTCEG score recompute
  4. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  7. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-09-14 09:01 UTCEG score recompute
  9. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-09-13 08:24 UTCEG score recompute
  11. 2026-09-12 03:34 UTCEG score recompute
  12. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  15. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  16. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-09-05 22:47 UTCEG score recompute
  18. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  19. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-08-30 07:30 UTCEG score recompute
  24. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  26. 2026-08-27 21:50 UTCEG score recompute
  27. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  28. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  29. 2026-08-26 08:23 UTCEG score recompute
  30. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  31. 2026-08-25 07:41 UTCEG score recompute
  32. 2026-08-23 06:21 UTCEG score recompute
  33. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  34. 2026-08-22 05:44 UTCEG score recompute
  35. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  36. 2026-08-21 05:07 UTCEG score recompute
  37. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  38. 2026-08-20 04:31 UTCEG score recompute
  39. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  40. 2026-08-19 03:54 UTCEG score recompute
  41. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  42. 2026-08-18 02:59 UTCEG score recompute
  43. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  44. 2026-08-17 01:31 UTCEG score recompute
  45. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  46. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  47. 2026-08-16 00:55 UTCEG score recompute
  48. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  49. 2026-08-13 23:42 UTCEG score recompute
  50. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  51. 2026-08-12 23:05 UTCEG score recompute
  52. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  53. 2026-08-11 22:29 UTCEG score recompute
  54. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  55. 2026-08-09 21:17 UTCEG score recompute
  56. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  57. 2026-08-08 20:41 UTCEG score recompute
  58. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  59. 2026-08-07 20:04 UTCEG score recompute
  60. 2026-08-06 19:28 UTCEG score recompute
  61. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  62. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  63. 2026-08-04 18:14 UTCEG score recompute
  64. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  65. 2026-08-04 10:39 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  66. 2026-08-03 17:33 UTCEG score recompute
  67. 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  68. 2026-08-02 16:55 UTCEG score recompute
  69. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  70. 2026-08-01 16:18 UTCEG score recompute
  71. 2026-08-01 04:16 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  72. 2026-07-31 15:42 UTCEG score recompute
  73. 2026-07-30 16:28 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  74. 2026-07-30 15:04 UTCEG score recompute
  75. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.4% · 27th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-59927?
CVE-2026-59927 is a medium-severity vulnerability; its CVE record was published on July 8, 2026. Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, allowing two markdown files that include each other to trigger unbounded recursion, raise…
When was the CVE record for CVE-2026-59927 published?
The CVE record for CVE-2026-59927 was published on July 8, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 9, 2026; the record at its source may have been updated since.
Is CVE-2026-59927 actively exploited?
CVE-2026-59927 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59927?
CVE-2026-59927 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-59927?
A fix for CVE-2026-59927 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-59927 are linked in the Vendor Advisories panel on this page.

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