Improper access control in Grafana - CVE-2026-33376
Published: May 18, 2026
Vulnerability identifier: #VU131637
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33376
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Grafana Labs
Affected software:
Grafana
Grafana
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass IP-based access restrictions for the Auth Proxy feature.
The vulnerability exists due to improper access control in the Auth Proxy IPv6 allow-list handling when evaluating IPv6 addresses without an explicitly specified mask. A remote attacker can use an IPv6 address that matches the unintended default /32 range to bypass IP-based access restrictions for the Auth Proxy feature.
Only the Auth Proxy feature is affected; other authentication methods such as Okta, SAML, and LDAP are unaffected.
How to mitigate CVE-2026-33376
Install security update from vendor's website.