Hashgraph Guardian through 3.6.0, fixed in commit ba8c566, contains a stored cross-site scripting vulnerability that allows authenticated users with the STANDARD_REGISTRY role to inject malicious scripts by submitting a crafted companyName value via the branding configuration API endpoint. Attackers can exploit the unsanitized innerHTML assignment in the branding service to execute arbitrary JavaScript in the browser of every authenticated user on every page load.
https://www.vulncheck.com/advisories/hashgraph-guardian-stored-xss-via-branding-companyname-field
https://github.com/hashgraph/guardian/pull/6190
https://github.com/hashgraph/guardian/commit/ba8c566807848cf84360716438056d8d8d2c8362
Published: 2026-06-18
Updated: 2026-06-23
Base Score: 4.7
Vector: CVSS2#AV:N/AC:L/Au:M/C:P/I:P/A:N
Severity: Medium
Base Score: 4.8
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 4.8
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Severity: Medium
EPSS: 0.00177