CVE-2026-83520

HIGHPre-NVD 8.88.8
EchelonGraph scoreHIGH confidence

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

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-10-13. The CNA's CVSS baseline 8.8; 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 week

Also known asEUVD-2026-100198 (ENISA EUVD) · GHSA-4w5f-7jp2-w48g (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
40
EG Risk 40/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation1.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
1.4%
EPSS %ILE
73rd
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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade 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; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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

October 13, 2026

Last Modified

October 31, 2026

Advisory Details (1)

Auto-updated Oct 13, 2026
Patch available. Sources: microsoft.
Microsoft

Security Update Guide - Microsoft Security Response Center

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83520

Vendor Advisories for CVE-2026-83520(3)

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

Patch Availability(5)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatdotnet8-0-main-8.0.132-0.1.hum12026-10-19redhat
nugetMicrosoft.WindowsDesktop.App.Runtime.win-arm64 @ 11.0.0-rc.2 (fixes >= 11.0.0-preview.1, <= 11.0.0-rc.1)—ghsa
nugetMicrosoft.WindowsDesktop.App.Runtime.win-arm64 @ 10.0.13 (fixes >= 10.0.0, <= 10.0.12)—ghsa
nugetMicrosoft.WindowsDesktop.App.Runtime.win-arm64 @ 8.0.32 (fixes >= 8.0.0, <= 8.0.31)—ghsa
nugetMicrosoft.WindowsDesktop.App.Runtime.win-arm64 @ 9.0.21 (fixes >= 9.0.0, <= 9.0.20)—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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× 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.

  1. 2026-11-01 07:38 UTCGHSA enrichmentGHSA-4w5f-7jp2-w48g · GitHub severity HIGH · GitHub CVSS 8.8
  2. 2026-11-01 07:38 UTCEG score recompute
  3. 2026-10-31 18:21 UTCEG score recompute
  4. 2026-10-31 18:21 UTCVendor advisory
  5. 2026-10-31 16:33 UTCEPSS rescoreEPSS 1.4% · 73rd percentile
  6. 2026-10-31 16:29 UTCVendor advisory
  7. 2026-10-30 19:22 UTCEG score recompute
  8. 2026-10-30 19:22 UTCVendor advisory
  9. 2026-10-30 16:35 UTCEPSS rescoreEPSS 1.4% · 73rd percentile
  10. 2026-10-29 16:34 UTCEPSS rescoreEPSS 1.4% · 73rd percentile
  11. 2026-10-29 15:31 UTCVendor advisory
  12. 2026-10-28 18:48 UTCEG score recompute
  13. 2026-10-28 18:48 UTCVendor advisory
  14. 2026-10-28 16:33 UTCEPSS rescoreEPSS 1.4% · 73rd percentile
  15. 2026-10-27 21:53 UTCVendor advisory
  16. 2026-10-27 20:56 UTCEG score recompute
  17. 2026-10-27 20:56 UTCVendor advisory
  18. 2026-10-27 16:32 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  19. 2026-10-26 19:41 UTCVendor advisory
  20. 2026-10-26 18:26 UTCEG score recompute
  21. 2026-10-26 18:26 UTCVendor advisory
  22. 2026-10-26 16:32 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  23. 2026-10-25 19:01 UTCVendor advisory
  24. 2026-10-25 17:25 UTCEG score recompute
  25. 2026-10-25 17:25 UTCVendor advisory
Show 43 more
  1. 2026-10-25 16:34 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  2. 2026-10-25 13:57 UTCEG score recompute
  3. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  4. 2026-10-23 22:41 UTCVendor advisory
  5. 2026-10-23 18:00 UTCEG score recompute
  6. 2026-10-23 18:00 UTCVendor advisory
  7. 2026-10-23 16:32 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  8. 2026-10-22 22:28 UTCEG score recompute
  9. 2026-10-22 22:28 UTCVendor advisory
  10. 2026-10-22 22:08 UTCEG score recompute
  11. 2026-10-22 22:08 UTCVendor advisory
  12. 2026-10-22 16:35 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  13. 2026-10-22 16:00 UTCVendor advisory
  14. 2026-10-21 21:22 UTCVendor advisory
  15. 2026-10-21 17:12 UTCEG score recompute
  16. 2026-10-21 17:12 UTCVendor advisory
  17. 2026-10-21 16:34 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  18. 2026-10-20 22:32 UTCVendor advisory
  19. 2026-10-20 18:59 UTCEG score recompute
  20. 2026-10-20 18:59 UTCVendor advisory
  21. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  22. 2026-10-20 00:08 UTCVendor advisory
  23. 2026-10-19 20:00 UTCEG score recompute
  24. 2026-10-19 20:00 UTCVendor advisory
  25. 2026-10-19 16:33 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  26. 2026-10-18 16:33 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  27. 2026-10-18 03:07 UTCEG score recompute
  28. 2026-10-17 16:35 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  29. 2026-10-16 17:53 UTCEG score recompute
  30. 2026-10-16 16:44 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  31. 2026-10-15 21:27 UTCEG score recompute
  32. 2026-10-15 16:33 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  33. 2026-10-14 17:09 UTCEG score recompute
  34. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.3% · 69th percentile
  35. 2026-10-14 04:33 UTCEG score recompute
  36. 2026-10-13 22:34 UTCEG score recompute
  37. 2026-10-13 21:41 UTCEG score recompute
  38. 2026-10-13 20:56 UTCEG score recompute
  39. 2026-10-13 19:58 UTCEG score recompute
  40. 2026-10-13 19:58 UTCVendor advisory
  41. 2026-10-13 19:23 UTCEG score recomputeFirst assessed: 8.8 HIGH
  42. 2026-10-13 19:23 UTCVendor advisory
  43. 2026-10-13 19:19 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-83520?
CVE-2026-83520 is a high-severity vulnerability; its CVE record was published on October 13, 2026. Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code over a network.
When was CVE-2026-83520 made public?
CVE-2026-83520 was made public on October 13, 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 October 13, 2026. EchelonGraph's copy of the record carries a last-modified date of October 31, 2026; the record at its source may have been updated since.
Is CVE-2026-83520 actively exploited?
CVE-2026-83520 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.4% probability of exploitation in the next 30 days (73rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-83520?
CVE-2026-83520 has a CVSS base score of 8.8 (the CNA's own assessment, by microsoft; NVD's own analysis pending).
How do I remediate CVE-2026-83520?
A fix for CVE-2026-83520 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-83520 are linked in the Vendor Advisories panel on this page.

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