Trestle SSTI in Jinja2 include tags allows arbitrary code execution (Incomplete fix of CVE-2026-46439)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.8 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-57170: 0.24% estimated exploitation activity in the next 30 days; percentile 14.50 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Reporter: Cavan Loughran, Celvex Group Inc. Summary ------- The fix for CVE-2026-46439 (3.12.2 / 4.0.3) removed the recursive re-render loop in trestle/core/commands/author/jinja.py rendertemplate, but the custom include tags in trestle/core/jinja/tags.py (MDSectionInclude, MDCleanInclude) still re-parse the CONTENT of an included markdown file as a Jinja2 template via Parser(self.environment, <file text).parse() in a plain (non-sandboxed) jinja2.Environment. Because the trestle markdown writers (sspio.py SSPMarkdownWriter, docscontrolwriter.py DocsControlWriter) write OSCAL prose / component-description fields verbatim (the {{ - [ neutralization is applied to parameter tables only), attacker-controlled OSCAL data that flows into an included markdown file is interpreted as template code and can achieve arbitrary code execution on the runner. This is the same trust boundary and impact as CVE-2026-46439 via a sink the fix did not cover. Affected versions ----------------- 4.0.3 and…

Published by the source

24 Sep 2026, 19:50 UTC

Last modified by the source

1 Oct 2026, 17:56 UTC

Source last checked

26 Oct 2026, 13:54 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-mr95-65j8-9mxp

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-mr95-65j8-9mxp

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-mr95-65j8-9mxp

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# Patch Next advisory brief: CVE-2026-57170

Advisory: Trestle SSTI in Jinja2 include tags allows arbitrary code execution (Incomplete fix of CVE-2026-46439)
IDs: CVE-2026-57170, GHSA-mr95-65j8-9mxp
Record: https://patchnext.com/advisories/cve-2026-57170 (revision 3, source checked 26 Oct 2026, 13:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: compliance-trestle 4.1.0, 3.12.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI compliance-trestle: affected < 3.12.4; >= 4.0.0, < 4.1.0; fixed in 3.12.4, 4.1.0

## Suggested inspection (read-only)
- `python -m pip show compliance-trestle`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on compliance-trestle.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-mr95-65j8-9mxp (GitHub-reviewed advisory GHSA-mr95-65j8-9mxp lists affected ranges: PyPI compliance-trestle >=0 =4.0.0 <4.1.0)
- Verified: https://osv.dev/vulnerability/GHSA-mr95-65j8-9mxp (OSV record GHSA-mr95-65j8-9mxp lists affected ranges: PyPI compliance-trestle >=0 =4.0.0 <4.1.0 (fixed))

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