Omnissa Workspace One UEM: server-side request forgery flaw under attack

What is affected

Omnissa Workspace One UEM is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.

Omnissa Workspace One UEM formerly known as VMware Workspace One UEM contains a server-side request forgery (SSRF) vulnerability that could allow a malicious actor with network access to UEM to send their requests without authentication and to gain access to sensitive information.

What an attacker can do

This is a server-side request forgery flaw. It lets an attacker make the server send requests on their behalf and reach internal systems that are not exposed to the internet.

How it is reached

Over the internet or network

Access the attacker needs

No account needed

Does the victim have to do something?

No, works without the victim doing anything

What to do

1. At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
2. If you administer Omnissa Workspace One UEM at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
3. If the product is past its support date and no fix exists, take it off the internet or retire it.

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

Vendor advisories and fixes

• web.archive.orgweb.archive.org/web/20211222154335/https://www.vmware.com/security/advisories/VMSA-2021-00

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on March 9, 2026, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by March 23, 2026, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 100% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 100.0% of all scored vulnerabilities.

Its CVSS severity score is 7.5 out of 10 (high), as recorded in the US National Vulnerability Database.

Technical description

VMware Workspace ONE UEM console 20.0.8 prior to 20.0.8.37, 20.11.0 prior to 20.11.0.40, 21.2.0 prior to 21.2.0.27, and 21.5.0 prior to 21.5.0.37 contain an SSRF vulnerability. This issue may allow a malicious actor with network access to UEM to send their requests without authentication and to gain access to sensitive information.