CVE-2026-59928

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-20. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this weekElevated

Also known asEUVD-2026-42338 (ENISA EUVD) · GHSA-ffq3-xpv3-j92q (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (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
0.7%
EPSS %ILE
51st
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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 public PoC (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.

The score's inputs: 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

October 25, 2026

Advisory Details (3)

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

block_parser: quadratic-time parsing on long lists of repeated reference-link definitions · Advisory · lepture/mistune · GitHub

https://github.com/lepture/mistune/security/advisories/GHSA-ffq3-xpv3-j92q
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 2b04d7ba341c (lepture/mistune)

Patch available: lepture/mistune v3.3.0 (contains commit 2b04d7ba341c)

https://github.com/lepture/mistune/commit/2b04d7ba341c16ac78fe82d3076bdd5c3de87c69

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
pipmistune @ 3.3.0 (fixes < 3.3.0)—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

(3 across 3 ecosystems)
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 11× in last 7d / 43× 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 177 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 77 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  2. 2026-11-02 04:38 UTCEG score recompute
  3. 2026-11-02 04:38 UTCGHSA enrichmentGHSA-ffq3-xpv3-j92q · GitHub severity HIGH · GitHub CVSS 7.5
  4. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  5. 2026-11-01 07:41 UTCGHSA enrichmentGHSA-ffq3-xpv3-j92q · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-11-01 07:41 UTCEG score recompute
  7. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  9. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  11. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  12. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  13. 2026-10-25 17:28 UTCEG score recompute
  14. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  15. 2026-10-25 14:16 UTCEG score recompute
  16. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  17. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  18. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  19. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  20. 2026-10-21 03:57 UTCEG score recompute
  21. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  22. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  23. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  24. 2026-10-18 03:27 UTCEG score recompute
  25. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.7% · 50th percentile
Show 75 more
  1. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  2. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  3. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  4. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  5. 2026-10-13 15:46 UTCEG score recompute
  6. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  7. 2026-10-12 15:52 UTCEG score recompute
  8. 2026-10-11 19:36 UTCEG score recompute
  9. 2026-10-11 16:51 UTCEG score recompute
  10. 2026-10-11 14:13 UTCEG score recompute
  11. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  12. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  14. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  15. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  17. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  19. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  20. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  21. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  22. 2026-10-01 16:11 UTCEG score recompute
  23. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  24. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  25. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  26. 2026-09-28 13:22 UTCEG score recompute
  27. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  28. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  29. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  30. 2026-09-24 11:48 UTCEG score recompute
  31. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  32. 2026-09-23 06:10 UTCEG score recompute
  33. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  34. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  35. 2026-09-18 05:43 UTCEG score recompute
  36. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  37. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  38. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  39. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  40. 2026-09-13 23:49 UTCEG score recompute
  41. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  42. 2026-09-13 08:24 UTCEG score recompute
  43. 2026-09-12 03:34 UTCEG score recompute
  44. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  45. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.7% · 49th percentile
  46. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  47. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  48. 2026-09-06 14:03 UTCEG score recompute
  49. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  50. 2026-09-05 22:48 UTCEG score recompute
  51. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  52. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  53. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  54. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  55. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  56. 2026-08-30 07:30 UTCEG score recompute
  57. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  58. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  59. 2026-08-27 21:50 UTCEG score recompute
  60. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  61. 2026-08-27 01:29 UTCEG score recompute
  62. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  63. 2026-08-26 08:23 UTCEG score recompute
  64. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.7% · 48th percentile
  65. 2026-08-25 00:30 UTCEG score recompute
  66. 2026-08-24 13:04 UTCEG score recompute
  67. 2026-08-23 02:40 UTCEG score recompute
  68. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  69. 2026-08-22 03:46 UTCEG score recompute
  70. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  71. 2026-08-21 03:59 UTCEG score recompute
  72. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  73. 2026-08-20 01:59 UTCEG score recompute
  74. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  75. 2026-08-18 22:28 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-59928?
CVE-2026-59928 is a high-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, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service…
When was the CVE record for CVE-2026-59928 published?
The CVE record for CVE-2026-59928 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 October 25, 2026; the record at its source may have been updated since.
Is CVE-2026-59928 actively exploited?
CVE-2026-59928 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (51st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59928?
CVE-2026-59928 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-59928?
A fix for CVE-2026-59928 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-59928 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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