Open redirect via redundant leading slashes
Published Feb 8, 2026 · Updated Feb 8, 2026
Open redirect in Doorman 0.1 through 0.6 allows remote attackers to send users to an external site via a crafted next parameter. The is_safe_url function accepts multiply slash-prefixed input because urljoin retains the application host, while browsers reinterpret the Location header as protocol-relative. Abuse requires a user to follow a crafted login link and complete or already have authentication, after which the browser leaves the trusted Doorman origin.
Summary
What happened
Open redirect in Doorman 0.1 through 0.6 allows remote attackers to send users to an external site via a crafted next parameter. The is_safe_url function accepts multiply slash-prefixed input because urljoin retains the application host, while browsers reinterpret the Location header as protocol-relative. Abuse requires a user to follow a crafted login link and complete or already have authentication, after which the browser leaves the trusted Doorman origin.
The record
- CVE
- CVE-2026-2153
- Published
- Feb 8, 2026
- Updated
- Feb 8, 2026
- Vendor
- Marcin Wielgoszewski
- Product
- Doorman
- Classifications
- CWE-601
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 8, 2026CVE publishedPublication date reported by the CVE source.
- Feb 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.1
- Affected versionversion=0.2
- Affected versionversion=0.3
- Affected versionversion=0.4
- Affected versionversion=0.5
- Affected versionversion=0.6
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Doorman redundant-slash open-redirect PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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