← Vulnerability feed

Vulnerability record · CVE-2026-75833 · published 18 August 2026

CVE-2026-75833: Open redirect vulnerability

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.

8.6 CVSS 4.0 High EPSS 0.22% · top 88.9% CWE-601 · Open redirect Deferred
8.6CVSS 4.0 base score
0.22%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
8 Sep 2026Last modified by NVD

Description

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/getgrav/grav/security/advisories/GHSA-x72c-4jc4-8rh6
https://www.vulncheck.com/advisories/grav-api-plugin-open-redirect-via-backslash-bypass

Track CVE-2026-75833 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

4.7CVE-2012-0518Oracle Fusion Middleware SSO open redirect flawOracle Fusion Middleware 10.1.4.3.0 contains an unspecified open redirect vulnerability in the Application Server Single Sign-On component, tracked a…KEVEPSS 4.7%analysed6.1CVE-2021-38000Google Chrome Android Intents input validation open redirectChrome on Android before 95.0.4638.69 fails to properly validate untrusted input passed through Intents, allowing a crafted HTML page to redirect the…KEVEPSS 4.9%analysed

Source: NIST National Vulnerability Database (record CVE-2026-75833), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.