CVE-2026-44889
Description
A flaw was found in WebOb, a library for HTTP requests and responses. A remote attacker could exploit this vulnerability by influencing the HTTP Location header during a redirect. Due to improper normalization of the Location header, specifically how certain ASCII characters are handled, an attacker can cause a user to be redirected to an arbitrary external website instead of the intended destination. This open redirect vulnerability can lead to information disclosure and impact the integrity of user sessions.
Statement
This is rated as Moderate (CVSS 6.1) because exploitation requires user interaction — a victim must click a crafted link that triggers the redirect (UI:R). While the attack is network-accessible (AV:N) and requires no privileges (PR:N), the impact is limited to low confidentiality and integrity effects typical of an open redirect (phishing, session misdirection), with no availability impact. Critically, this vulnerability is only exploitable on Python 3.10 or later, where urllib.parse.urlsplit strips tab, carriage return, and newline characters before parsing. All Red Hat product streams that ship python-webob — including Red Hat OpenShift Container Platform, Red Hat OpenStack Platform, Red Hat Ceph Storage, and Red Hat Quay — use Python 3.9 or earlier as the platform runtime, and are therefore not affected. Fedora and EPEL ship python-webob under Python 3.12+ and are affected. Users running WebOb on Python 3.10+ should upgrade to version 1.8.10, or validate that redirect targets include an explicit scheme with the expected host before assigning to Response.location.
Mitigation
This vulnerability in WebOb is only exploitable when running under Python 3.10 or later, where urllib.parse.urlsplit strips ASCII tab, carriage return, and newline characters before parsing. Red Hat Enterprise Linux, OpenShift Container Platform, Red Hat OpenStack Platform, Red Hat Ceph Storage, and Red Hat Quay all ship python-webob with Python 3.9 or earlier as the platform Python runtime, and are therefore not affected by this vulnerability. Fedora and EPEL ship python-webob under Python 3.12+, where the vulnerability is exploitable. Users running WebOb on Python 3.10+ should upgrade to WebOb 1.8.10. As a workaround, applications can validate that redirect targets start with a scheme (e.g. http:// or https://) and the expected host before assigning to Response.location.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.1 | N/A | 6.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Changed | N/A | Changed |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
The user may be redirected to an untrusted page that contains malware which may then compromise the user's system. In some cases, an open redirect can also enable the immediate download of a file without the user's permission, because the redirection to an external site may lead to endpoints on those sites that automatically trigger a download action ("drive-by download" [REF-1478]). This will expose the user to extensive risk. The user's interaction with the web server may also be compromised if the malware conducts keylogging or other attacks that steal credentials, personally identifiable information (PII), or other important data.
Access Control,Confidentiality,Other
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity; Other
By modifying the URL value to a malicious site, an attacker may successfully launch a phishing scam. The user may be subjected to phishing attacks by being redirected to an untrusted page. The phishing attack may point to an attacker controlled web page that appears to be a trusted web site. The phishers may then steal the user's credentials and then use these credentials to access the legitimate web site. Because the server name in the modified link is identical to the original site, phishing attempts have a more trustworthy appearance.
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