vciy

CVE-2021-31176

INDEX BUILT · 2026-09-20

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Microsoft Office Remote Code Execution Vulnerability

CVE-2021-311764 of 4 sources documented this
24

rank 24 = 1 + 17 + 1 + 5 + 0

rank@v1 · backlog

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.03047  ·  without this subject the record ranks 23

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 6.8, from NVD  ·  without this subject the record ranks 7

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

rose on 2026-02-08  ·  without this subject the record ranks 23

How much of the world it touches

NVD CPE configurations

4 products in the CPE ranges  ·  without this subject the record ranks 19

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 24

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$152,000over the next 30 days, if this record is yours
Movement+$221,000on 2026-02-08, the last material move, 4 months before this reading
Basisassumeda published average, not your estate

$152,000 = $4.99M incident cost x 1 exposure x 0.03047 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.03047EPSSNOT IN KEVas of 2026-09-20
Severity7.8 HIGHreceipt
Harmtotal lossreceipt
Exploitationnone in held sources
Defensefix version namedreceipt
Movementthreshold crossedreceipt
RISING10Risen from 0.00918 to 0.03047 across 57 observations. arc-rules@v1

Foresight · where to check next

CVE-2018-15982Adobe FlashCVE-2013-2551Microsoft WindowsMicrosoft WindowsMicrosoft Windows31176

This record is one instance of CWE-416, use after free. The index holds 8701 prior instances of this class, 106 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1

Full pattern panel

Prior records in this weakness class. Each is its own record, dated and receipted.
Color is a claim, not decoration:the hostile worldthe defenseno signalspoke length is how much of the record matches, not how bad it is

Sources disagree here.

Severity score
Microsoft7.8 HIGHreceipt
NVD6.8 MEDIUMreceipt
Scoring standard
MicrosoftCVSS v3.1receipt
NVDCVSS v2.0receipt

Both shown, dated. We don't pick winners. disagreement-rules@v1

Running Microsoft Office 2019? Check your version

A deterministic range check against the ranges this record publishes. It tells you where a version sits in the record, not whether your deployment is exploitable. No account needed.

Watch this record

Matches your own product list against every record this index holds, and tells you when one of them moves.

What counts as a move

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Record your call

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Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachneeds local access · no privileges required · user interaction required · low attack complexityreceipt
ImpactComplete confidentiality, integrity and availability lossreceipt
Scored fromCVSS v3.1 · the CNA's vectorreceipt
Weakness classCWE-416 Use After Freereceipt
Published consequencesCWE-416: Integrity: Modify Memory; Availability: DoS: Crash, Exit, or Restart; Confidentiality: Read Memory; Integrity, Confidentiality, Availability: Execute Unauthorized Code or Commands[email protected]

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

Fixed in16.0.5161.1002; 15.0.5345.1002receipt
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.

Exploit Status & Known PoCs a ladder, not a score

Current rung: Nothing observed in held sources.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, the CNA7.8 HIGHreceipt
CVSS, NVD6.8 MEDIUMreceipt
Exploit probability0.03047 · top 13% of all CVEsreceipt
Blast breadth2 products across 1 vendorderived
Assigned bymicrosoftreceipt
Recorded changes57 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productMicrosoft Office 2019; Microsoft 365 Apps for Enterprise; Microsoft Office 2016; Microsoft Office 2013 Service Pack 1receipt
Published rangesmicrosoft office 2013; microsoft office 2016; microsoft office 2019; microsoft office web apps server 2013receipt
Fixed in16.0.5161.1002; 15.0.5345.1002receipt

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

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What it is stated by the CNA

Microsoft Office Remote Code Execution Vulnerability receipt

NVD's analysis a second authority

severity
6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
weakness
CWE-416
affected versions
microsoft office 2013; microsoft office 2016; microsoft office 2019; and 1 more, listed in full below
also scored by
[email protected] 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H · [email protected] 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

The CNA scored it 7.8 and NVD 6.8. Both are shown because both were published; we do not pick one.

check it yourself portal.msrc.microsoft.com zerodayinitiative.com receipt

Dated events

2021-05-18EPSS moved 0.01 to 0.142022-01-06EPSS moved 0.14 to 0.422026-06-15EPSS moved 0.16 to 0.03

Movement the material steps

12 May 20210.00918
18 May 20210.13741 · crossed 0.10
6 Jan 20220.41682
4 Feb 20220.3168
1 Apr 20220.04475 · crossed 0.10
7 Mar 20230.00353 · scoring model v2023.03.01
17 Mar 20250.01369 · scoring model v2025.03.14
8 Feb 20260.10465 · crossed 0.10
15 Jun 20260.03047 · crossed 0.10 · scoring model v2026.06.15
Show all 57 observations
12 May 20210.00918
14 May 20210.01374
18 May 20210.13741
6 Jan 20220.41682
4 Feb 20220.3168
1 Apr 20220.04475
27 Nov 20220.04844
7 Mar 20230.00353
14 Mar 20230.00339
28 Mar 20230.00326
26 Apr 20230.00371
19 Jul 20230.00598
3 Aug 20230.00466
15 Aug 20230.00485
31 Aug 20230.00474
12 Sep 20230.00656
27 Sep 20230.00459
11 Oct 20230.00638
24 Oct 20230.01860
7 Nov 20230.00721
20 Nov 20230.01640
4 Dec 20230.01437
16 Dec 20230.01601
12 Jan 20240.01002
25 Jan 20240.01029
20 Feb 20240.01248
6 Mar 20240.01005
2 Apr 20240.00978
16 Apr 20240.01033
13 Jun 20240.01216
27 Jun 20240.01116
12 Jul 20240.00948
28 Jul 20240.01048
12 Aug 20240.00878
27 Aug 20240.00981
13 Sep 20240.00731
17 Dec 20240.00882
10 Feb 20250.01287
28 Feb 20250.00900
15 Mar 20250.01566
17 Mar 20250.01369
19 Mar 20250.0134
25 Mar 20250.02197
29 Mar 20250.03175
30 Mar 20250.02197
9 Apr 20250.02029
12 Jun 20250.03397
3 Aug 20250.04543
2 Oct 20250.06044
18 Nov 20250.07026
21 Nov 20250.06044
8 Feb 20260.10465
1 Apr 20260.13571
30 May 20260.13922
31 May 20260.14024
1 Jun 20260.15526
15 Jun 20260.03047

57 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.03047Published2021-05-11Index as of2026-06-15

The record had been public for 5 years, 1 month when this index was last written.

Published 2021-05-11 receipt · Index as of 2026-06-15 derived

The pattern, elsewhere

This record is one instance of CWE-416, use after free. The index holds 8701 prior instances of this class, 106 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2018-15982matches 8 of 8KEV listed · 2019receipt
CVE-2018-4878 · Adobe Flash Player before 28.0.0.161matches 8 of 9KEV listed · 2018receipt
CVE-2013-2551matches 7 of 8KEV listed · 2013receipt
CVE-2025-29824 · Microsoft Windows 10 Version 1507matches 7 of 9KEV listed · 2025receipt
CVE-2021-40449 · Microsoft Windows 10 Version 1809matches 7 of 9KEV listed · 2021receipt
CVE-2019-0708 · Microsoft Windowsmatches 7 of 9KEV listed · 2019receipt

"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1

8701 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.

No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.

Siblings and hubs

Records related to this one

Its defect family

microsoft office 2019

Of the 14 records in this family, this is the only one holding a stated fix version: 16.0.5161.1002; 15.0.5345.1002.

Grouped by shared product and weakness, not by shared vulnerability. Each record's own state is on its own page.

Family membership: computed, pro@dim2000

This record is one of a group, and the group's page describes all of them. This page is kept and dated, and the defect family's own page is the one we offer for indexing: the whole group.

Browse the index from here

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What usually comes next

Everything above needs no account. What is below is work: assembling it, scoping it to your estate, watching it, and handing it to someone else.

Everything on this page is free. Public data. Withholding it protects nothing.