CVE-2026-33819

CRITICALNVD 9.810.0
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-04-24. NVD baseline CVSS 9.8; sources differ by 0.2.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 5 sources updated this week

Also known asEUVD-2026-25311 (ENISA EUVD) · GHSA-97j9-4xhc-69qj (GitHub Security Advisories)Source: ENISA EUVD

10.0EG
EchelonGraph verdictPlan mitigationRemediate 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: 0.8%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.

CVSS v3
9.8
EG Score
10.0CRITICALmedium confidence
EG Risk
60
EG Risk 60/100

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)
Severity100% × 45%
Impact severity (EG Severity): CVSS 10.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.8% × 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 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 referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines at low or medium mission impact and sooner than that at high; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
EPSS PROB
0.8%
EPSS %ILE
57th
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 (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.

EG Severity
10.0 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). 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 referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines at low or medium mission impact and sooner than that at high; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

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

April 23, 2026

Last Modified

October 26, 2026

Advisory Details (1)

Auto-updated Oct 27, 2026
Fix referenced — no release confirmed yet. Sources: microsoft.
Microsoft

Security Update Guide - Microsoft Security Response Center

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33819

Vendor Advisories for CVE-2026-33819(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 26× in last 7d / 81× 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 99 of 483 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 384 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 22:11 UTCEG score recompute
  2. 2026-10-29 22:11 UTCVendor advisory
  3. 2026-10-29 22:11 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  5. 2026-10-28 21:57 UTCEG score recompute
  6. 2026-10-28 21:57 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  7. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  8. 2026-10-27 21:44 UTCEG score recompute
  9. 2026-10-27 21:43 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  10. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  11. 2026-10-26 21:27 UTCEG score recompute
  12. 2026-10-26 21:27 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  13. 2026-10-26 21:27 UTCNVD updateCVSS v3 → 9.8
  14. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  15. 2026-10-25 23:04 UTCEG score recompute
  16. 2026-10-25 23:04 UTCVendor advisory
  17. 2026-10-25 23:04 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  18. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.8% · 57th percentile
  19. 2026-10-25 14:34 UTCEG score recompute
  20. 2026-10-24 22:49 UTCEG score recompute
  21. 2026-10-24 22:49 UTCVendor advisory
  22. 2026-10-24 22:49 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  23. 2026-10-24 16:32 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  24. 2026-10-23 22:36 UTCEG score recompute
  25. 2026-10-23 22:36 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
Show 74 more
  1. 2026-10-23 16:31 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  2. 2026-10-22 22:12 UTCEG score recompute
  3. 2026-10-22 22:12 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  4. 2026-10-22 16:34 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  5. 2026-10-21 21:50 UTCEG score recompute
  6. 2026-10-21 21:50 UTCVendor advisory
  7. 2026-10-21 21:50 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  8. 2026-10-21 16:32 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  9. 2026-10-20 21:14 UTCEG score recompute
  10. 2026-10-20 21:14 UTCVendor advisory
  11. 2026-10-20 21:14 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  12. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  13. 2026-10-19 20:59 UTCEG score recompute
  14. 2026-10-19 20:59 UTCVendor advisory
  15. 2026-10-19 20:59 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  16. 2026-10-19 16:31 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  17. 2026-10-18 19:24 UTCEG score recompute
  18. 2026-10-18 19:24 UTCVendor advisory
  19. 2026-10-18 19:24 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  20. 2026-10-18 16:31 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  21. 2026-10-18 03:46 UTCEG score recompute
  22. 2026-10-17 19:09 UTCEG score recompute
  23. 2026-10-17 19:09 UTCVendor advisory
  24. 2026-10-17 19:09 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  25. 2026-10-17 16:34 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  26. 2026-10-16 18:53 UTCEG score recompute
  27. 2026-10-16 18:53 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  28. 2026-10-16 16:41 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  29. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  30. 2026-10-15 15:57 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  31. 2026-10-14 23:19 UTCEG score recompute
  32. 2026-10-14 23:19 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  33. 2026-10-14 16:32 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  34. 2026-10-14 10:15 UTCEG score recompute
  35. 2026-10-14 10:15 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  36. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  37. 2026-10-13 08:41 UTCEG score recompute
  38. 2026-10-13 08:41 UTCVendor advisory
  39. 2026-10-13 08:40 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  40. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  41. 2026-10-12 16:13 UTCEG score recompute
  42. 2026-10-12 08:24 UTCVendor advisory
  43. 2026-10-12 08:23 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  44. 2026-10-11 19:55 UTCEG score recompute
  45. 2026-10-11 17:08 UTCEG score recompute
  46. 2026-10-11 14:35 UTCEG score recompute
  47. 2026-10-11 13:48 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  48. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  49. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  50. 2026-10-08 17:12 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  51. 2026-10-07 23:47 UTCEPSS rescoreEPSS 1.5% · 74th percentile
  52. 2026-10-06 15:17 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  53. 2026-10-05 17:42 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  54. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  55. 2026-10-03 14:25 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  56. 2026-10-01 19:49 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  57. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  58. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  59. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  60. 2026-09-26 15:58 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  61. 2026-09-26 00:26 UTCEPSS rescoreEPSS 1.5% · 73rd percentile
  62. 2026-09-25 17:44 UTCEG score recompute
  63. 2026-09-25 17:44 UTCVendor advisory
  64. 2026-09-25 17:44 UTCGHSA enrichmentGHSA-97j9-4xhc-69qj · GitHub severity CRITICAL · GitHub CVSS 10.0
  65. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  66. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  67. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  68. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.8% · 56th percentile
  69. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  70. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  71. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  72. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  73. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.8% · 55th percentile
  74. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.8% · 55th percentile

Frequently asked(5)

What is CVE-2026-33819?
CVE-2026-33819 is a critical-severity vulnerability; its CVE record was published on April 23, 2026. Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.
When was CVE-2026-33819 made public?
CVE-2026-33819 was made public on April 23, 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 April 23, 2026. EchelonGraph's copy of the record carries a last-modified date of October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-33819 actively exploited?
CVE-2026-33819 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (57th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33819?
CVE-2026-33819 has a CVSS v3 base score of 9.8 (NVD). EchelonGraph synthesises NVD + FIRST EPSS + GHSA into a combined EG score of 10.0 (CRITICAL).
How do I remediate CVE-2026-33819?
A fix for CVE-2026-33819 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation. The vendor advisories EchelonGraph has for CVE-2026-33819 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-33819

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