CVE-2026-54770
Description
A flaw was found in WebOb, a library for HTTP requests and responses. This vulnerability allows an unauthenticated attacker to bypass URL validation checks by injecting leading control characters or spaces into a redirect target. This can lead to an open redirect, enabling attackers to send users to malicious websites for phishing or to steal OAuth and Single Sign-On (SSO) tokens. Exploitation requires the user to follow the crafted redirect.
Statement
This is an open redirect vulnerability in the WebOb library. An unauthenticated attacker can craft a malicious URL that, when processed by applications utilizing WebOb for redirects, bypasses URL validation. This could lead to users being redirected to attacker-controlled sites, facilitating phishing attacks or the theft of authentication tokens, provided the user follows the redirect.
Mitigation
Applications utilizing the WebOb library should implement strict validation of redirect target URLs. Configure applications to only allow redirects to trusted, fully-qualified URIs or to strictly allowlist permitted redirect destinations. Reject any redirect target that does not begin with an expected trusted host or a validated relative path, ensuring no leading whitespace or control characters are present.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | 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 | High | N/A | Low |
| Integrity Impact | None | 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:H/I:N/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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