CVE-2026-54770
WebOb: Open redirect in Location header normalization via leading C0 control / space characters
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.
INFO
Published Date :
Aug. 20, 2026, 5:18 p.m.
Last Modified :
Aug. 20, 2026, 5:18 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-54770
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update WebOb to version 1.8.11.
- Ensure redirect targets are properly validated.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54770.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54770 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54770
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54770 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54770 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 20, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Pylons', 'product': 'webob', 'versions': [{'status': 'affected', 'version': '< 1.8.11'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-601 Added Reference https://github.com/Pylons/webob/commit/ff89560643fb252751b4db8806a283b5377f1f07 Added Reference https://github.com/Pylons/webob/security/advisories/GHSA-6hx8-3wjj-gr8g Added Reference https://github.com/Pylons/webob/tree/1.8.11