CVE-2026-49820 is a medium-severity open redirect vulnerability in go.probo.inc/probo (go), affecting versions < 0.204.0. It is fixed in 0.204.0.
Impact Probo's saferedirect package validates redirect URLs used across authentication flows (OIDC, SAML, session transfer, OAuth connectors, and trust-center magic links). The validator only inspected the second character of relative paths, so a URL like /../\evil.com passed validation because the second character is .. Go's http.Redirect normalizes this path to /\evil.com before setting the Location header. Browsers can interpret the backslash as a host separator and redirect the user to an external domain (https://evil.com), bypassing the intended same-origin restriction. This enables open-redirect phishing: an attacker can craft a continue parameter (or embed a malicious URL in a session-transfer token) that appears to originate from a trusted Probo domain but redirects victims elsewhere. Patches Fixed in go.probo.inc/probo by normalizing relative paths with path.Clean before validation, rejecting backslashes (including percent-encoded %5c) anywhere in the path, and re-checking the normalized result for protocol-relative and backslash prefixes. Self-hosted deployments should upgrade to probod v0.194.1 or later. SaaS deployments on getprobo.com are patched. Workarounds No practical workaround for self-hosted installations. Upgrade to the patched release.
Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.
CVE-2026-49820 has a CVSS score of 4.7 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (0.204.0). Upgrading removes the vulnerable code path.
go
go.probo.inc/probo (< 0.204.0)go.probo.inc/probo → 0.204.0 (go)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-49820 is reachable in your applications. Explore open-source security for your team.
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Already deployed Kodem? See CVE-2026-49820 in your environment →Upgrade go.probo.inc/probo to 0.204.0 or later to resolve this vulnerability.
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CVE-2026-49820 is a medium-severity open redirect vulnerability in go.probo.inc/probo (go), affecting versions < 0.204.0. It is fixed in 0.204.0. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
CVE-2026-49820 has a CVSS score of 4.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
go.probo.inc/probo (go) versions < 0.204.0 is affected.
Yes. CVE-2026-49820 is fixed in 0.204.0. Upgrade to this version or later.
Whether CVE-2026-49820 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade go.probo.inc/probo to 0.204.0 or later.