{"cve":"CVE-2026-54770","nvd":{"published":"2026-08-20T17:18:18.277","modified":"2026-10-18T20:10:00.110","status":"Deferred","description":"WebOb provides objects for HTTP requests and responses. Prior to 1.8.11, Response._make_location_absolute() in src/webob/response.py checks a Location value for a URI scheme or leading double slash before urllib.parse.urljoin() strips leading C0 control characters and spaces. An attacker-controlled value such as a space followed by a protocol-relative or absolute URL can therefore bypass SCHEME_RE and startswith(\"//\") checks and be normalized to an off-host redirect. Request.relative_url() and webob.exc._HTTPMove subclasses, including HTTPFound, are also affected because they use the same unsafe URL joining behavior or bypass the earlier normalization path. An unauthenticated attacker who can influence an application's redirect target can send users to an attacker-controlled host for phishing or OAuth and SSO token theft, but exploitation requires the user to follow the redirect. This issue is fixed in version 1.8.11.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-601"],"references":["https://github.com/Pylons/webob/commit/ff89560643fb252751b4db8806a283b5377f1f07","https://github.com/Pylons/webob/security/advisories/GHSA-6hx8-3wjj-gr8g","https://github.com/Pylons/webob/tree/1.8.11","https://github.com/Pylons/webob/security/advisories/GHSA-6hx8-3wjj-gr8g"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-54770","score":0.00421,"percentile":0.36162,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-6hx8-3wjj-gr8g","url":"https://osv.dev/vulnerability/GHSA-6hx8-3wjj-gr8g","summary":"WebOb: Open redirect in Location header normalization via leading C0 control / space characters","modified":"2026-09-10T12:26:08.196935251Z","packages":[{"ecosystem":"PyPI","name":"webob","purl":"pkg:pypi/webob","ranges":["<1.8.11"],"fixed":["1.8.11"]}]},{"id":"PYSEC-2026-3943","url":"https://osv.dev/vulnerability/PYSEC-2026-3943","summary":"WebOb: Open redirect in Location header normalization via leading C0 control / space characters","modified":"2026-09-10T12:15:13.320787314Z","packages":[{"ecosystem":"PyPI","name":"webob","purl":"pkg:pypi/webob","ranges":["<1.8.11"],"fixed":["1.8.11"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}