CVE-2026-49820 (GCVE-0-2026-49820)

Vulnerability from cvelistv5 – Published: 2026-08-13 14:36 – Updated: 2026-08-14 15:40
VLAI
Title
Probo has an open redirect bypass via path normalization
Summary
Probo is a self-hostable governance, risk, and compliance (GRC) platform built for engineering and security teams. Probo's `saferedirect` package validates redirect URLs used across authentication flows (OIDC, SAML, session transfer, OAuth connectors, and trust-center magic links). Prior to version 0.19.3.1, 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. This is fixed in `go.probo.inc/probo` 0.193.1 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. No practical workaround is available for self-hosted installations.
Severity
4.7 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-14 15:40 UTC
CWE
  • CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7664 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
getprobo probo Affected: < 0.193.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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