Contao up to 5.3.49/5.7.11 Request Token Validation RequestTokenListener act/key cross-site request forgery

Summaryinfo

A vulnerability, which was classified as problematic, was found in Contao up to 5.3.49/5.7.11. This vulnerability affects the function RequestTokenListener of the component Request Token Validation. Such manipulation of the argument act/key leads to cross-site request forgery. This vulnerability is uniquely identified as CVE-2026-107848. The attack can be launched remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Contao up to 5.3.49/5.7.11 and classified as problematic. Affected by this issue is the function RequestTokenListener of the component Request Token Validation. The manipulation of the argument act/key with an unknown input leads to a cross-site request forgery vulnerability. Using CWE to declare the problem leads to CWE-352. The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. Impacted is integrity. CVE summarizes:

Contao is an Open Source CMS. From version 4.0.0 until 5.3.50 and 5.7.12, RequestTokenListener validates REQUEST_TOKEN only for POST requests, while the declarative GET guard runs only when an act parameter is present. Backend actions dispatched through the key parameter can therefore execute without a CSRF token when an authenticated backend user loads an attacker-controlled URL. Reachable actions remain limited to modules available to that user, and the advisory demonstrates destructive or state-changing actions rather than privilege escalation. This issue is fixed in versions 5.3.50 and 5.7.12.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-107848 since 10/09/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

Upgrading to version 5.3.50 or 5.7.12 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• Contao

Version

• 5.3.0
• 5.3.1
• 5.3.2
• 5.3.3
• 5.3.4
• 5.3.5
• 5.3.6
• 5.3.7
• 5.3.8
• 5.3.9
• 5.3.10
• 5.3.11
• 5.3.12
• 5.3.13
• 5.3.14
• 5.3.15
• 5.3.16
• 5.3.17
• 5.3.18
• 5.3.19
• 5.3.20
• 5.3.21
• 5.3.22
• 5.3.23
• 5.3.24
• 5.3.25
• 5.3.26
• 5.3.27
• 5.3.28
• 5.3.29
• 5.3.30
• 5.3.31
• 5.3.32
• 5.3.33
• 5.3.34
• 5.3.35
• 5.3.36
• 5.3.37
• 5.3.38
• 5.3.39
• 5.3.40
• 5.3.41
• 5.3.42
• 5.3.43
• 5.3.44
• 5.3.45
• 5.3.46
• 5.3.47
• 5.3.48
• 5.3.49
• 5.7.0
• 5.7.1
• 5.7.2
• 5.7.3
• 5.7.4
• 5.7.5
• 5.7.6
• 5.7.7
• 5.7.8
• 5.7.9
• 5.7.10
• 5.7.11

Website

• Product: https://github.com/contao/contao/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion