Open redirect via control-character URL normalization
Published Jun 22, 2026 · Updated Jun 22, 2026
Open redirect in WebOb before 1.8.10 allows remote attackers to send users to external sites through crafted redirect targets. Response._make_location_absolute passes control-character-prefixed Location values to urllib.parse.urljoin, which strips the characters and accepts an attacker-controlled authority. Exploitation requires an application to place attacker-influenced data in Response.location and a user to follow the resulting redirect, enabling phishing without direct server compromise.
Summary
What happened
Open redirect in WebOb before 1.8.10 allows remote attackers to send users to external sites through crafted redirect targets. Response._make_location_absolute passes control-character-prefixed Location values to urllib.parse.urljoin, which strips the characters and accepts an attacker-controlled authority. Exploitation requires an application to place attacker-influenced data in Response.location and a user to follow the resulting redirect, enabling phishing without direct server compromise.
The record
- CVE
- CVE-2026-44889
- Published
- Jun 22, 2026
- Updated
- Jun 22, 2026
- Vendor
- Pylons Project
- Product
- WebOb
- Classifications
- CWE-601, CAPEC-178, T1566.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 22, 2026CVE publishedPublication date reported by the CVE source.
- Jun 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.8.10
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- PyPI Verified URL Open Redirect Vulnerability Chainproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo