Probo has an open redirect bypass via path normalization (CVE-2026-49820) | HOL Guard CVE

Medium · CVSS 4.7CVE-2026-49820GHSA-X7QQ-M748-8P2C

Probo has an open redirect bypass via path normalization

Answer in brief

CVE-2026-49820 records a Medium severity (CVSS 4.7) vulnerability in Probo has an open redirect bypass via path normalization. The current sources do not mark it as known exploited. The current feed maps getprobo/probo (generic), go.probo.inc/probo (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 13, 2026Updated Aug 14, 2026Source checked Sep 17, 2026First seen by HOL Jun 30, 2026Material review Aug 14, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.7
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 4.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps getprobo/probo (generic), go.probo.inc/probo (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
getprobo/probogeneric	< 0.193.1	Not reported
go.probo.inc/probogo	<0.204.0	0.204.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for getprobo/probo, go.probo.inc/probo.
Review the reported fix. Update go.probo.inc/probo to 0.204.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jun 30, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.