CVE-2026-20963

CRITICALNVD 9.89.8
EchelonGraph scoreHIGH confidence

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

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-03-18), indicating real-world exploitation has been confirmed by US federal agencies. It is also listed on ENISA's EU Known Exploited Vulnerabilities catalogue (Source: ENISA EUVD). NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, ENISA's EU Known Exploited Vulnerabilities catalogue, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this weekExploited in the wild

Also known asEUVD-2026-2114 (ENISA EUVD) · GHSA-5vr8-9cf6-r7px (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low mission impact
CISA-KEV: ExploitedENISA EU KEV: Listed (Source: ENISA EUVD)EPSS PROB: 29%CVSS: 9.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100

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.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low mission impact; Act at medium or high.
Exploitation active (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 sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
29%
EPSS %ILE
98th
KEV
⚠ Exploited

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.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
29% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and ENISA EU KEV (Source: ENISA EUVD) and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Act at medium mission impactAttend at low mission impact; Act at medium or high.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

ENISA EU KEV: listed March 12, 2026, reported by cnw.

Source: ENISA EUVD (EU Known Exploited Vulnerabilities catalogue), reproduced with acknowledgement. How a listing moves the EG score

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low mission impact; Act at medium or high.

A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.

Exploitation active (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 & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.

The score's inputs: In CISA KEV yes (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

CISA required action“Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963 · https://nvd.nist.gov/vuln/detail/CVE-2026-20963

Published

January 13, 2026

Last Modified

July 30, 2026

Advisory Details (2)

Auto-updated Oct 30, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Patch available. Sources: microsoft.
Microsoft

Security Update Guide - Microsoft Security Response Center

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963
CISA🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20963

Vendor Advisories for CVE-2026-20963(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 24× in last 7d / 194× 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 1,772 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 1,672 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 15:44 UTCEG score recompute
  2. 2026-11-01 15:44 UTCVendor advisory
  3. 2026-11-01 15:44 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  4. 2026-10-31 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
  5. 2026-10-31 15:27 UTCEG score recompute
  6. 2026-10-31 15:27 UTCVendor advisory
  7. 2026-10-31 15:27 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  8. 2026-10-30 16:34 UTCEPSS rescoreEPSS 29% · 98th percentile
  9. 2026-10-30 15:11 UTCEG score recompute
  10. 2026-10-30 15:11 UTCVendor advisory
  11. 2026-10-30 15:11 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  12. 2026-10-29 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
  13. 2026-10-29 14:55 UTCEG score recompute
  14. 2026-10-29 14:55 UTCVendor advisory
  15. 2026-10-29 14:55 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  16. 2026-10-28 16:31 UTCEPSS rescoreEPSS 29% · 98th percentile
  17. 2026-10-28 14:39 UTCEG score recompute
  18. 2026-10-28 14:39 UTCVendor advisory
  19. 2026-10-28 14:39 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  20. 2026-10-27 16:31 UTCEPSS rescoreEPSS 29% · 98th percentile
  21. 2026-10-27 14:21 UTCEG score recompute
  22. 2026-10-27 14:21 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  23. 2026-10-26 14:05 UTCEG score recompute
  24. 2026-10-26 14:05 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  25. 2026-10-25 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
Show 75 more
  1. 2026-10-25 13:47 UTCEG score recompute
  2. 2026-10-25 13:47 UTCVendor advisory
  3. 2026-10-25 13:47 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  4. 2026-10-25 13:46 UTCENISA EU KEV listingEUVD-2026-2114 · listed March 12, 2026 · reported by cnw · Source: ENISA EUVD
  5. 2026-10-25 09:44 UTCEG score recompute
  6. 2026-10-25 09:44 UTCVendor advisory
  7. 2026-10-25 09:44 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  8. 2026-10-24 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
  9. 2026-10-24 09:28 UTCEG score recompute
  10. 2026-10-24 09:28 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  11. 2026-10-23 16:31 UTCEPSS rescoreEPSS 29% · 98th percentile
  12. 2026-10-23 09:11 UTCEG score recompute
  13. 2026-10-23 09:11 UTCVendor advisory
  14. 2026-10-23 09:11 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  15. 2026-10-22 16:34 UTCEPSS rescoreEPSS 29% · 98th percentile
  16. 2026-10-22 08:55 UTCEG score recompute
  17. 2026-10-22 08:54 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  18. 2026-10-21 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
  19. 2026-10-21 08:37 UTCEG score recompute
  20. 2026-10-21 08:37 UTCVendor advisory
  21. 2026-10-21 08:37 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-20 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
  23. 2026-10-20 08:20 UTCEG score recompute
  24. 2026-10-20 08:20 UTCVendor advisory
  25. 2026-10-20 08:20 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  26. 2026-10-19 16:31 UTCEPSS rescoreEPSS 29% · 98th percentile
  27. 2026-10-19 08:03 UTCEG score recompute
  28. 2026-10-19 08:03 UTCVendor advisory
  29. 2026-10-19 08:03 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  30. 2026-10-18 07:46 UTCVendor advisory
  31. 2026-10-18 07:46 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  32. 2026-10-18 03:56 UTCEG score recompute
  33. 2026-10-17 16:33 UTCEPSS rescoreEPSS 29% · 98th percentile
  34. 2026-10-17 07:29 UTCEG score recompute
  35. 2026-10-17 07:29 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  36. 2026-10-16 16:41 UTCEPSS rescoreEPSS 29% · 98th percentile
  37. 2026-10-16 07:11 UTCEG score recompute
  38. 2026-10-16 07:11 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  39. 2026-10-15 16:31 UTCEPSS rescoreEPSS 29% · 98th percentile
  40. 2026-10-15 06:54 UTCEG score recompute
  41. 2026-10-15 06:54 UTCVendor advisory
  42. 2026-10-15 06:54 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-10-14 16:32 UTCEPSS rescoreEPSS 29% · 98th percentile
  44. 2026-10-14 06:37 UTCEG score recompute
  45. 2026-10-14 06:36 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  46. 2026-10-13 16:33 UTCEPSS rescoreEPSS 29% · 98th percentile
  47. 2026-10-13 06:17 UTCEG score recompute
  48. 2026-10-13 06:17 UTCVendor advisory
  49. 2026-10-13 06:17 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  50. 2026-10-12 16:33 UTCEPSS rescoreEPSS 29% · 98th percentile
  51. 2026-10-12 16:23 UTCEG score recompute
  52. 2026-10-12 06:01 UTCVendor advisory
  53. 2026-10-12 06:01 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  54. 2026-10-12 01:48 UTCVendor advisory
  55. 2026-10-12 01:48 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  56. 2026-10-11 21:36 UTCVendor advisory
  57. 2026-10-11 21:36 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  58. 2026-10-11 20:05 UTCEG score recompute
  59. 2026-10-11 17:24 UTCVendor advisory
  60. 2026-10-11 17:23 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  61. 2026-10-11 17:18 UTCEG score recompute
  62. 2026-10-11 14:50 UTCEG score recompute
  63. 2026-10-11 13:48 UTCEPSS rescoreEPSS 29% · 98th percentile
  64. 2026-10-11 13:11 UTCEG score recompute
  65. 2026-10-11 13:11 UTCVendor advisory
  66. 2026-10-11 13:10 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  67. 2026-10-11 08:59 UTCVendor advisory
  68. 2026-10-11 08:59 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  69. 2026-10-11 04:47 UTCVendor advisory
  70. 2026-10-11 04:46 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  71. 2026-10-11 00:33 UTCVendor advisory
  72. 2026-10-11 00:33 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-10-10 20:19 UTCEG score recompute
  74. 2026-10-10 20:19 UTCVendor advisory
  75. 2026-10-10 20:19 UTCGHSA enrichmentGHSA-5vr8-9cf6-r7px · GitHub severity HIGH · GitHub CVSS 8.8

Frequently asked(6)

What is CVE-2026-20963?
CVE-2026-20963 is a critical-severity vulnerability; its CVE record was published on January 13, 2026. Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
When was CVE-2026-20963 made public?
CVE-2026-20963 was made public on January 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 January 13, 2026. EchelonGraph's copy of the record carries a last-modified date of July 30, 2026; the record at its source may have been updated since.
Is CVE-2026-20963 actively exploited?
Yes. CISA added CVE-2026-20963 to the Known Exploited Vulnerabilities catalog on March 18, 2026, affecting Microsoft SharePoint. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it. ENISA's EU Known Exploited Vulnerabilities catalogue lists CVE-2026-20963 (added March 12, 2026, reported by cnw): ENISA records its exploitation in the wild. Source: ENISA EUVD (EU Known Exploited Vulnerabilities catalogue), reproduced with acknowledgement.
What is the CVSS score of CVE-2026-20963?
CVE-2026-20963 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2026-20963?
CVE-2026-20963 affects Microsoft SharePoint.
How do I remediate CVE-2026-20963?
A fix for CVE-2026-20963 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-20963 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-20963

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