CVE-2026-86429

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 2026-09-07. 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 — 4 sources updated this week

Also known asEUVD-2026-72387 (ENISA EUVD) · GHSA-7x8h-jg2x-pjm5 (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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

The league/commonmark (thephpleague/commonmark) library in versions >= 1.5.0 and < 2.9.1 contains quadratic parsing complexity in its SmartPunctExtension and AttributesExtension. When either extension is explicitly registered on the Environment (they are not enabled by default and are excluded from the standard CommonMark and GitHub-Flavored Markdown converters), an unauthenticated attacker can submit small, specially crafted Markdown documents — such as text alternating with unpaired quotes, contiguous runs of block-level attribute blocks, or repeated class attributes — to trigger disproportionate CPU consumption and cause a denial of service. Fixed in 2.9.1.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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.
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

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
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-28). 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 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.

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

September 7, 2026

Last Modified

October 8, 2026

Advisory Details (2)

Auto-updated Sep 7, 2026
Patch available. Sources: github.
Web page

commonmark before 2.9.1 Denial of Service via SmartPunct and Attributes | Advisories | VulnCheck

https://www.vulncheck.com/advisories/commonmark-before-2.9.1-denial-of-service-via-smartpunct-and-attributes
GitHub advisoryMentions a patch (unverified)

Denial of service in the SmartPunct and Attributes extensions · Advisory · thephpleague/commonmark · GitHub

Affected: 2.9.0.

https://github.com/thephpleague/commonmark/security/advisories/GHSA-jjv6-8j6v-6j52

Vendor Advisories for CVE-2026-86429(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
php-league-commonmark2.10.0-1 ... 2.9.0-1 (25 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
php-league-commonmark2.10.0-1 ... 2.9.0-1 (13 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
php-league-commonmark2.7.0-1 ... 2.9.0-1 (9 versions)
  • every version up to 2.10.0-1: fixed in 2.10.0-1
—
Packagist(1)
PackageVulnerable rangeFix by version rangeDependents
league/commonmark1.5.0 ... 2.9.0 (66 versions)
  • 1.5.0 up to 2.9.1: fixed in 2.9.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 68× 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 174 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 74 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  4. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-10-28 21:43 UTCEG score recompute
  7. 2026-10-28 21:43 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  8. 2026-10-28 18:55 UTCOSV refresh
  9. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-10-25 13:54 UTCEG score recompute
  14. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  16. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  18. 2026-10-20 21:24 UTCEG score recompute
  19. 2026-10-20 21:24 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  20. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-10-18 03:04 UTCEG score recompute
  24. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
Show 75 more
  1. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  2. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  3. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  4. 2026-10-13 05:20 UTCEG score recompute
  5. 2026-10-13 05:19 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  6. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  7. 2026-10-12 14:51 UTCEG score recompute
  8. 2026-10-11 19:17 UTCEG score recompute
  9. 2026-10-11 16:33 UTCEG score recompute
  10. 2026-10-11 13:51 UTCEG score recompute
  11. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  12. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  13. 2026-10-10 09:46 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-10-09 22:45 UTCEG score recompute
  15. 2026-10-09 22:45 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  16. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-10-09 03:37 UTCEG score recompute
  18. 2026-10-09 03:37 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  19. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-10-08 16:34 UTCEG score recompute
  21. 2026-10-08 16:34 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  22. 2026-10-08 15:39 UTCEG score recompute
  23. 2026-10-08 15:39 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  24. 2026-10-08 09:39 UTCEG score recompute
  25. 2026-10-08 09:39 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  26. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  27. 2026-10-07 22:39 UTCEG score recompute
  28. 2026-10-07 22:39 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  29. 2026-10-07 05:52 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  30. 2026-10-06 18:52 UTCEG score recompute
  31. 2026-10-06 18:52 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  32. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  33. 2026-10-06 07:52 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  34. 2026-10-05 20:53 UTCEG score recompute
  35. 2026-10-05 20:53 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  36. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  37. 2026-10-05 09:54 UTCEG score recompute
  38. 2026-10-05 09:54 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  39. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  40. 2026-10-04 22:54 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  41. 2026-10-04 11:54 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  42. 2026-10-04 00:53 UTCEG score recompute
  43. 2026-10-04 00:53 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  44. 2026-10-03 12:25 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  45. 2026-10-03 00:21 UTCEG score recompute
  46. 2026-10-03 00:21 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-10-02 12:47 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  48. 2026-10-02 00:29 UTCEG score recompute
  49. 2026-10-02 00:29 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  50. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  51. 2026-10-01 13:18 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  52. 2026-10-01 02:18 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  53. 2026-09-30 15:19 UTCEG score recompute
  54. 2026-09-30 15:19 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  55. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  56. 2026-09-30 02:30 UTCEG score recompute
  57. 2026-09-30 02:30 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  58. 2026-09-29 09:18 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  59. 2026-09-28 22:18 UTCEG score recompute
  60. 2026-09-28 22:18 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  61. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  62. 2026-09-28 11:14 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  63. 2026-09-28 00:14 UTCEG score recompute
  64. 2026-09-28 00:14 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  66. 2026-09-27 13:14 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-09-27 02:14 UTCEG score recompute
  68. 2026-09-27 02:14 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  69. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  70. 2026-09-26 15:14 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  71. 2026-09-26 03:39 UTCEG score recompute
  72. 2026-09-26 03:38 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  73. 2026-09-25 16:22 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  74. 2026-09-25 05:22 UTCGHSA enrichmentGHSA-7x8h-jg2x-pjm5 · GitHub severity HIGH · GitHub CVSS 7.5
  75. 2026-09-24 18:22 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-86429?
CVE-2026-86429 is a high-severity vulnerability; its CVE record was published on September 7, 2026. The league/commonmark (thephpleague/commonmark) library in versions >= 1.5.0 and < 2.9.1 contains quadratic parsing complexity in its SmartPunctExtension and AttributesExtension. When either extension is explicitly registered on the Environment (they are not enabled by default and are excluded from…
When was CVE-2026-86429 made public?
CVE-2026-86429 was made public on August 9, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on September 7, 2026. EchelonGraph's copy of the record carries a last-modified date of October 8, 2026; the record at its source may have been updated since.
Is CVE-2026-86429 actively exploited?
CVE-2026-86429 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-2026-86429?
CVE-2026-86429 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-2026-86429?
A fix for CVE-2026-86429 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-86429 are linked in the Vendor Advisories panel on this page.

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