Threat Intelligence Database

CVE-2026-54770 is an open redirect vulnerability in the Pylons webob library prior to version 1.8.11. The issue arises from improper validation and normalization of redirect URLs in Response._make_location_absolute() and related methods, allowing attacker-controlled values to bypass scheme and leading double slash checks. This can lead to redirects to attacker-controlled sites, potentially enabling phishing or token theft if users follow the redirect. The vulnerability is fixed in version 1.8.11.

A security update addresses multiple issues in several Python packages including python-Markdown, python-joblib, python-handy-archives, python-apache-libcloud, python-WebOb, python-PyGithub, and python-soupsieve. Notably, python-WebOb fixes a security vulnerability (CVE-2026-44889) related to open redirect via Location header normalization during redirects. Other changes mainly involve test fixes and compatibility updates with recent Python versions. No known exploits are reported in the wild.

WebOb provides objects for HTTP requests and responses. Prior to 1.8.10, the normalization of the HTTP Location header during a redirect is vulnerable to an open redirect: WebOb joins the redirect target to the request URI using Python's urljoin, and since Python 3.10 the underlying urlsplit strips ASCII tab, carriage return, and newline characters before parsing, so a redirect target containing such characters can be reinterpreted as a protocol-relative URL whose authority is an attacker-controlled host. This bypasses the CVE-2024-42353 fix that escaped a leading double slash, allowing an attacker who influences the redirect location to send users to an arbitrary external site instead of the intended one. This vulnerability is fixed in 1.8.10.