CVE-2026-32201
CVE-2026-32201 is a security flaw in Microsoft SharePoint Server, Microsoft’s software for company intranets and shared documents. Attackers can make something fake look genuine in Microsoft SharePoint Server. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 14 Apr 2026.[1]
Microsoft SharePoint Server is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version 16.0.5548.1003, 16.0.10417.20114 and 16.0.19725.20210.
Description
CISA calls it an improper input validation in Microsoft SharePoint Server. In its words: “Microsoft SharePoint Server contains an improper input validation vulnerability that allows an unauthorized attacker to perform spoofing over a network.”[1]
The underlying weakness is improper input validation (CWE-20), in MITRE’s list of common software weaknesses.[2]
It scores 6.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| Microsoft SharePoint Enterprise Server 2016 | 16.0.5548.1003 |
| Microsoft SharePoint Server 2019 | 16.0.10417.20114 |
| Microsoft SharePoint Server Subscription Edition | 16.0.19725.20210 |
Most families won’t have Microsoft SharePoint Server; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 14 Apr 2026, within a day of it being made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 28 Apr 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 43%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Microsoft has published a fix or advice.[3] CISA’s 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.”[1]
- Check whether you use it.Microsoft SharePoint Server is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version 16.0.5548.1003, 16.0.10417.20114 and 16.0.19725.20210), or not in use. CISA gave US government agencies until 28 Apr 2026 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 6.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 43%.[4] |
See also
Other Microsoft SharePoint Server flaws
- CVE-2026-56164: missing authentication for critical function ·
- CVE-2026-45659: deserialization of untrusted data ·
- CVE-2023-24955: code injection ·
- CVE-2023-29357: privilege escalation ·
Other Microsoft flaws
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2026-65660, Microsoft SharePoint: code injection ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2026-81963, Microsoft Windows: link following ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
Other improper input validation flaws
- CVE-2026-93952, Arista VeloCloud Orchestrator: improper input validation ·
- CVE-2026-12569, PTC Windchill and FlexPLM: improper input validation ·
- CVE-2026-34910, Ubiquiti UniFi OS: improper input validation ·
- CVE-2026-6973, Ivanti Endpoint Manager Mobile (EPMM): improper input validation ·
- CVE-2026-34197, Apache ActiveMQ: improper input validation ·
Added the same day
- CVE-2009-0238, Microsoft Office: remote code execution ·
Every Microsoft flaw on CISA’s list · Everything added in April 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft SharePoint Server Improper Input Validation Vulnerability”. Known Exploited Vulnerabilities Catalog, added 14 Apr 2026.
- ^ National Institute of Standards and Technology. “CVE-2026-32201 Detail”. National Vulnerability Database, published 14 Apr 2026.
- ^ Microsoft. Advisories and fixes: msrc.microsoft.com, msrc.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.434, percentile 98.7, 31 Oct 2026.
- CVE Program. “CVE-2026-32201”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.