openrun CVE-2026-55252
MEDIUM
GHSA-h5g6-xmh4-hc37
Severity by source
Network-accessible, no privileges needed; UI:R because victim must follow crafted link; I:L for deceptive redirect; no confidentiality or availability impact on the server.
Estimated by vuln.today — no official severity rating has been published for this CVE yet.
Lifecycle Timeline
1DescriptionCVE.org
Summary
The restrictions on redirect URLs in openrun can be bypassed by attackers, leading to open redirect attacks.
Details
In the current project, the referrer header value is used for subsequent redirects, so there is currently a validation for this redirect value. The current validation logic requires that the host and schema of the redirect URL be the same as the current website's URL, and finally, the path part is used for redirection. This check seems robust, but it can still be bypassed by attackers.
<img width="1606" height="1346" alt="QQ20260602-140205-2-2" src="https://github.com/user-attachments/assets/83c549f3-38d7-444d-90f0-131d806f67ff" />
Here's the problem: Assuming the current website is http://127.0.0.1:25222/, if the attacker passes in a redirect URL of http://127.0.0.1:25222//fushuling.com, its host and schema are obviously the same as the current website, thus bypassing the verification. However, the issue lies in the final redirect URL, which is the path part of the URL, i.e., //fushuling.com.
Browsers automatically complete the HTTP header for URLs starting with //, ultimately successfully bypassing the restriction and redirecting to the external address http://fushuling.com.
This vulnerable behavior was successfully reproduced locally. Normally, specifying an external address directly will be blocked, so it will not redirect.
<img width="1587" height="717" alt="QQ20260602-140756-2-3" src="https://github.com/user-attachments/assets/51430c42-bd10-401b-9c9f-27a91a0bc648" />
However, if the redirect URL is http://127.0.0.1:25222//fushuling.com, the existing validation logic is bypassed, and the Location header is successfully set to //fushuling.com.
POST /redirecttest/abc/frag HTTP/1.1
Host: 127.0.0.1:25222
Referer: http://127.0.0.1:25222//fushuling.com
Cache-Control: max-age=0
sec-ch-ua: "Not(A:Brand";v="24", "Chromium";v="122"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Windows"
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.6261.57 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
Sec-Fetch-Site: none
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 0
<img width="1536" height="729" alt="QQ20260602-140925-2-4" src="https://github.com/user-attachments/assets/31fde919-5f90-409f-8b14-af6c9c71761b" />
The user was then successfully redirected to the external address http://fushuling.com.
<img width="1692" height="855" alt="QQ20260602-141005-2-5" src="https://github.com/user-attachments/assets/83b43ef6-52fa-4218-908b-7795394ae707" />
PoC
http://127.0.0.1:25222//fushuling.comImpact
Open Redirect
AnalysisAI
Open redirect bypass in openrun prior to v0.17.7 allows remote unauthenticated attackers to redirect victims to arbitrary external URLs by exploiting a double-slash path prefix that evades the application's host/scheme validation. The referrer-based redirect logic correctly validates the host and scheme but passes the extracted path //attacker.com to the Location header, which browsers interpret as a protocol-relative URL and resolve to an external destination. A proof-of-concept is publicly documented in the security advisory; no active exploitation has been confirmed by CISA KEV at time of analysis.
Technical ContextAI
openrun (pkg:go/github.com_openrundev_openrun) is a Go application that uses the HTTP Referer header to drive post-action redirects. Its validation logic extracts the host and scheme from the Referer value and compares them to the application's own origin - a pattern intended to prevent external redirects. However, the implementation fails to sanitize the path component before constructing the Location header response. When a Referer of http://[host]//attacker.com is submitted, the host and scheme checks pass (they match the server), but the extracted path is //attacker.com. RFC-compliant browsers (Chrome, Firefox, Safari, Edge - all represented in the advisory tags) treat a Location value beginning with // as a scheme-relative reference and prepend the current protocol (http or https), completing the redirect to http://attacker.com. This is a textbook CWE-601 (URL Redirection to Untrusted Site / Open Redirect) caused by incomplete input validation that checks necessary but not sufficient properties of the URL.
RemediationAI
Upgrade openrun to v0.17.7 or later, which incorporates the fix in commit 709da784fcf1311c85f30f3542cfa3601a78bbf0 (https://github.com/openrundev/openrun/commit/709da784fcf1311c85f30f3542cfa3601a78bbf0); the release is available at https://github.com/openrundev/openrun/releases/tag/v0.17.7. If immediate patching is not feasible, apply a server-side Referer sanitization rule that rejects or strips any Referer path component beginning with // or containing consecutive slashes after the host - this eliminates the specific bypass vector. Additionally, enforcing a strict allowlist of permitted redirect paths (rather than a blocklist approach) provides a more robust long-term defense and removes the entire bypass class, though it requires enumeration of all legitimate redirect targets. No side effects are expected from the path-prefix filter; an allowlist approach may require configuration effort to enumerate valid paths.
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Vendor StatusVendor
SUSE
| Product | Status |
|---|---|
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
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External POC / Exploit Code
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