Exploitation evidence
Known exploited · CISA KEV listed
Added 2022-03-28. Ransomware campaign use: Known.
CISA required action: Apply updates per vendor instructions.
CISA due date: 2022-04-18. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
Microsoft / Microsoft 365 Apps for Enterprise
Default status: Not specified
- affected: 16.0.1 to < https://aka.ms/OfficeSecurityReleases (custom)
Microsoft / Microsoft Office 2013 Service Pack 1
Default status: Not specified
- affected: 15.0.0 to < 5381.1000 (custom)
Microsoft / Microsoft Office 2016
Default status: Not specified
- affected: 16.0.0 to < 5215.1000 (custom)
Microsoft / Microsoft Office 2019
Default status: Not specified
- affected: 19.0.0 to < https://aka.ms/OfficeSecurityReleases (custom)
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.07987,
"percentile": 0.94836
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.07987,
"percentile": 0.94804
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.07987,
"percentile": 0.94797
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.07987,
"percentile": 0.94795
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.07987,
"percentile": 0.94791
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.07987,
"percentile": 0.94782
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.07987,
"percentile": 0.94778
}05 Nov 2026, 06:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
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],
"title": "Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability"
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}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.07987,
"percentile": 0.94774
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.07987,
"percentile": 0.94765
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.07987,
"percentile": 0.94758
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2021-38646",
"cwes": [],
"dateAdded": "2022-03-28",
"dueDate": "2022-04-18",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Known",
"notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-38646",
"product": "Office",
"requiredAction": "Apply updates per vendor instructions.",
"shortDescription": "Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.",
"vendorProject": "Microsoft",
"vulnerabilityName": "Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability"
}