oscal-compass compliance-trestle up to 3.12.3/4.0.3 Jinja2 Include Tags tags.py parse special elements in template engine

Summaryinfo

A vulnerability classified as problematic was found in oscal-compass compliance-trestle up to 3.12.3/4.0.3. Affected by this vulnerability is the function parse of the file Trestle/core/jinja/tags.py of the component Jinja2 Include Tags. The manipulation results in special elements in template engine. This vulnerability is reported as CVE-2026-57170. The attack requires a local approach. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in oscal-compass compliance-trestle up to 3.12.3/4.0.3. Affected is the function parse of the file Trestle/core/jinja/tags.py of the component Jinja2 Include Tags. The manipulation with an unknown input leads to a special elements in template engine vulnerability. CWE is classifying the issue as CWE-1336. The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Compliance-trestle (Trestle) is a Python SDK and command-line tool for managing OSCAL compliance documents. In versions prior to 3.12.4 and 4.0.0 through 4.0.3, the custom Jinja2 include tags mdsection_include and md_clean_include re-parse the content of an included Markdown file as Jinja2 template code in a non-sandboxed environment, allowing server-side template injection that can lead to arbitrary code execution. The MDSectionInclude and MDCleanInclude tags in Trestle/core/jinja/tags.py pass included file content to Parser(self.environment, ...).parse(), splicing it into the host template's compilation, and the environment is a plain jinja2.Environment rather than a SandboxedEnvironment, so any expressions in the file are evaluated with full access to the usual SSTI gadget chain. Because Trestle's Markdown writers emit OSCAL prose and component-description fields verbatim, applying delimiter neutralization only to parameter tables, attacker-controlled OSCAL data such as a control statement, part prose, or component description containing Jinja2 syntax flows into an included Markdown file and is executed when the include tag re-parses it. This issue is fixed in version 4.1.0.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-57170 since 06/24/2026. The exploitability is told to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1221.

Upgrading to version 4.1.0 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• oscal-compass

Name

• compliance-trestle

Version

• 3.12.0
• 3.12.1
• 3.12.2
• 3.12.3
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3

Website

• Product: https://github.com/oscal-compass/compliance-trestle/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion