CVE-2021-22538

8.8 highEPSS 0.7%

High (8.8) in google exposure notifications verification server. EPSS 0.7% chance of exploitation in the next 30 days. Fixed in github.com/google/exposure-notifications-verification-server 0.23.1.

A privilege escalation vulnerability impacting the Google Exposure Notification Verification Server (versions prior to 0.23.1), allows an attacker who (1) has UserWrite permissions and (2) is using a carefully crafted request or malicious proxy, to create another user with higher privileges than their own. This occurs due to insufficient checks on the allowed set of permissions. The new user creation event would be captured in the Event Log.

Severity

CVSS 3.1

8.8 high

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.7% chance of exploitation in the next 30 days; higher than 53% of CVEs (scores of 2026-10-31)
CWEs: CWE-276, CWE-20
Published: 2021-03-31
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

google:exposure_notifications_verification_server

Packages (OSV)

Advisory	Ecosystem	Package	Affected	Fixed in
GHSA-5v95-v8c8-3rh6	Go	github.com/google/exposure-notifications-verification-server	<0.23.1	0.23.1
GO-2022-0798	Go	github.com/google/exposure-notifications-verification-server	<0.23.1	0.23.1

References

Check your stack JSON