GetGrav up to 1.0.13 SSO Controller sanitizeReturnTo returnTo redirect

Summaryinfo

A vulnerability marked as problematic has been reported in GetGrav Grav up to 1.0.13. This issue affects the function SsoController::sanitizeReturnTo of the component SSO Controller. This manipulation of the argument returnTo causes redirect. The identification of this vulnerability is CVE-2026-75833. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in GetGrav Grav up to 1.0.13 and classified as problematic. Affected by this vulnerability is the function SsoController::sanitizeReturnTo of the component SSO Controller. The manipulation of the argument returnTo with an unknown input leads to a redirect vulnerability. The CWE definition for the vulnerability is CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. As an impact it is known to affect integrity. The summary by CVE is:

The Grav API plugin (getgrav/grav-plugin-api, bundled with Grav 2.0's admin-next/API stack) before version 1.0.14 contains an open redirect weakness in SsoController::sanitizeReturnTo(). The function rejects a literal '//' prefix but does not account for browsers normalizing backslashes to slashes in special (http/https) schemes, so a returnTo value such as '/\evil.com' passes the guard and is later resolved by the browser as the protocol-relative URL '//evil.com'. Following a legitimate OAuth login flow, an attacker-supplied returnTo parameter could redirect an authenticated victim to an attacker-controlled site for post-login phishing. Full browser-side exploitability depends on the admin-next SPA's client-side oauth-callback handler and was not independently verified by the reporter.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-75833 since 08/18/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1204.001 for this issue.

Upgrading to version 1.0.14 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• GetGrav

Name

• Grav

Version

• 1.0.0
• 1.0.1
• 1.0.2
• 1.0.3
• 1.0.4
• 1.0.5
• 1.0.6
• 1.0.7
• 1.0.8
• 1.0.9
• 1.0.10
• 1.0.11
• 1.0.12
• 1.0.13

Website

• Product: https://github.com/getgrav/grav/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion