CVE-2026-55824
Contao crawler leaks auth credentials to external hosts
Description
Contao is an Open Source CMS. In versions 4.13.40 through 5.3.46 and 5.7.0-RC1 through 5.7.6, the crawler leaks auth credentials to external hosts. Contao's crawler tries to prevent confidential HTTP client options from being sent to external domains by creating a scoped client: full options for root page origins, cleaned options for everything else. The cleaner removes Cookie and Authorization headers, but it removes the non-Symfony option names basic_auth and bearer_auth instead of Symfony HttpClient's real auth_basic and auth_bearer options. When contao.crawl.default_http_client_options contains Basic or Bearer authentication for a protected staging/production site, those credentials remain in the "clean" client used for external links or configured additional URIs. An attacker who can get an external URL crawled, for example through a link on a crawled page while the broken-link checker is enabled, can receive the crawler credentials. This issue has been fixed in versions 5.3.47 and 5.7.7.
INFO
Published Date :
July 31, 2026, 7:17 p.m.
Last Modified :
July 31, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-55824
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 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 3.1 | LOW | MITRE-CVE |
Solution
- Update Contao to version 5.3.47 or higher.
- Update Contao to version 5.7.7 or higher.
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-2026-55824.
| URL | Resource |
|---|---|
| https://github.com/contao/contao/security/advisories/GHSA-3mr9-p497-58f6 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-55824 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-2026-55824
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-2026-55824 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-55824 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.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 31, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-55824', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-31T19:58:23.916842Z'} -
New CVE Received by [email protected]
Jul. 31, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'contao', 'product': 'contao', 'versions': [{'status': 'affected', 'version': '>= 4.13.40, < 5.3.47'}, {'status': 'affected', 'version': '>= 5.7.0-RC1, < 5.7.7'}]}] Added Description Contao is an Open Source CMS. In versions 4.13.40 through 5.3.46 and 5.7.0-RC1 through 5.7.6, the crawler leaks auth credentials to external hosts. Contao's crawler tries to prevent confidential HTTP client options from being sent to external domains by creating a scoped client: full options for root page origins, cleaned options for everything else. The cleaner removes Cookie and Authorization headers, but it removes the non-Symfony option names basic_auth and bearer_auth instead of Symfony HttpClient's real auth_basic and auth_bearer options. When contao.crawl.default_http_client_options contains Basic or Bearer authentication for a protected staging/production site, those credentials remain in the "clean" client used for external links or configured additional URIs. An attacker who can get an external URL crawled, for example through a link on a crawled page while the broken-link checker is enabled, can receive the crawler credentials. This issue has been fixed in versions 5.3.47 and 5.7.7. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N Added CWE CWE-200 Added Reference https://github.com/contao/contao/security/advisories/GHSA-3mr9-p497-58f6