CVE-2026-47291

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-09. The CNA's CVSS baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: the CNA's CVSS, EPSS, GitHub Security Advisory
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-35501 (ENISA EUVD) · GHSA-392q-pc37-m552 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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).
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 25%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

A fix is available — apply it.

Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
75
EG Risk 75/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 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 none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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
25%
EPSS %ILE
97th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
25% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: 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 total (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)3 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 total (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

June 9, 2026

Last Modified

September 24, 2026

Advisory Details (1)

Auto-updated Oct 31, 2026
Patch available. Sources: microsoft.
Microsoft

Security Update Guide - Microsoft Security Response Center

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47291

Vendor Advisories for CVE-2026-47291(2)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 85× 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 768 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 668 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 10:44 UTCEG score recompute
  2. 2026-10-31 10:44 UTCVendor advisory
  3. 2026-10-31 10:44 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-30 16:34 UTCEPSS rescoreEPSS 25% · 97th percentile
  5. 2026-10-30 12:36 UTCEG score recompute
  6. 2026-10-30 12:36 UTCVendor advisory
  7. 2026-10-30 12:35 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-10-29 16:33 UTCEPSS rescoreEPSS 25% · 97th percentile
  9. 2026-10-29 14:24 UTCEG score recompute
  10. 2026-10-29 14:24 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-28 16:32 UTCEPSS rescoreEPSS 25% · 97th percentile
  12. 2026-10-28 16:16 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-27 18:07 UTCEG score recompute
  14. 2026-10-27 18:07 UTCVendor advisory
  15. 2026-10-27 18:07 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-10-27 16:32 UTCEPSS rescoreEPSS 25% · 97th percentile
  17. 2026-10-26 19:58 UTCEG score recompute
  18. 2026-10-26 19:57 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-26 16:31 UTCEPSS rescoreEPSS 25% · 97th percentile
  20. 2026-10-25 19:43 UTCEG score recompute
  21. 2026-10-25 19:43 UTCVendor advisory
  22. 2026-10-25 19:43 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-25 16:33 UTCEPSS rescoreEPSS 25% · 97th percentile
  24. 2026-10-25 14:24 UTCEG score recompute
  25. 2026-10-24 21:34 UTCEG score recompute
Show 75 more
  1. 2026-10-24 21:34 UTCVendor advisory
  2. 2026-10-24 21:34 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  4. 2026-10-23 23:26 UTCEG score recompute
  5. 2026-10-23 23:26 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-23 16:31 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  7. 2026-10-23 01:02 UTCEG score recompute
  8. 2026-10-23 01:01 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-22 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  10. 2026-10-22 02:18 UTCEG score recompute
  11. 2026-10-22 02:18 UTCVendor advisory
  12. 2026-10-22 02:18 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  14. 2026-10-21 03:50 UTCEG score recompute
  15. 2026-10-21 03:50 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  17. 2026-10-20 05:38 UTCEG score recompute
  18. 2026-10-20 05:38 UTCVendor advisory
  19. 2026-10-20 05:37 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-19 16:32 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  21. 2026-10-19 07:20 UTCEG score recompute
  22. 2026-10-19 07:20 UTCVendor advisory
  23. 2026-10-19 07:20 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-18 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  25. 2026-10-18 09:10 UTCVendor advisory
  26. 2026-10-18 09:10 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  27. 2026-10-18 03:36 UTCEG score recompute
  28. 2026-10-17 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  29. 2026-10-17 10:53 UTCEG score recompute
  30. 2026-10-17 10:53 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-16 16:42 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  32. 2026-10-16 12:28 UTCEG score recompute
  33. 2026-10-16 12:28 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  34. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  35. 2026-10-15 14:17 UTCEG score recompute
  36. 2026-10-15 14:17 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  38. 2026-10-14 09:01 UTCEG score recompute
  39. 2026-10-14 09:01 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  40. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  41. 2026-10-13 05:40 UTCEG score recompute
  42. 2026-10-13 05:40 UTCVendor advisory
  43. 2026-10-13 05:40 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  44. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  45. 2026-10-12 16:02 UTCEG score recompute
  46. 2026-10-12 07:31 UTCVendor advisory
  47. 2026-10-12 07:31 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  48. 2026-10-11 19:44 UTCEG score recompute
  49. 2026-10-11 16:59 UTCEG score recompute
  50. 2026-10-11 14:24 UTCEG score recompute
  51. 2026-10-11 13:48 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  52. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  53. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  54. 2026-10-08 17:12 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  55. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  56. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  57. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  58. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  59. 2026-10-03 14:25 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  60. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  61. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  62. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  63. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  64. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  65. 2026-09-26 00:27 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  66. 2026-09-24 14:09 UTCEG score recompute
  67. 2026-09-24 14:09 UTCVendor advisory
  68. 2026-09-24 14:09 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-09-23 17:53 UTCEPSS rescoreEPSS 23% · 97th percentile
  70. 2026-09-18 19:28 UTCEPSS rescoreEPSS 23% · 97th percentile
  71. 2026-09-16 14:08 UTCEPSS rescoreEPSS 23% · 97th percentile
  72. 2026-09-16 05:15 UTCEPSS rescoreEPSS 23% · 97th percentile
  73. 2026-09-14 08:40 UTCVendor advisory
  74. 2026-09-14 08:40 UTCGHSA enrichmentGHSA-392q-pc37-m552 · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-09-14 04:30 UTCEG score recompute

Publicly available exploits

(1 reference)

Public exploit code is referenced for this CVE (1 GitHub PoC). Defenders should treat patch urgency accordingly.

  • GitHub PoCManagerEmpty/CVE-2026-47291-httpsys
    Published Jun 10, 2026

    HTTP.sys RCE

    Open source ↗

Frequently asked(5)

What is CVE-2026-47291?
CVE-2026-47291 is a critical-severity vulnerability; its CVE record was published on June 9, 2026. Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.
When was CVE-2026-47291 made public?
CVE-2026-47291 was made public on June 9, 2026: that is the date its CVE record's CNA, Microsoft Corporation, gives for when the vulnerability was made public. The CVE record itself was published on June 9, 2026. EchelonGraph's copy of the record carries a last-modified date of September 24, 2026; the record at its source may have been updated since.
Is CVE-2026-47291 actively exploited?
CVE-2026-47291 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 25% probability of exploitation in the next 30 days (97th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-47291?
CVE-2026-47291 has a CVSS base score of 9.8 (the CNA's own assessment, by microsoft; NVD's own analysis pending).
How do I remediate CVE-2026-47291?
A fix for CVE-2026-47291 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-47291 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-47291

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