# CVE-2026-71291: Bolt CMS Server-Side Template Injection via Unsandboxed allow_twig Field Rendering

> Attackers can execute arbitrary code by injecting Twig templates into fields with allow_twig enabled, as Bolt CMS lacks sandboxing.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-m6xj-xx3f-5vv9

## What is CVE-2026-71291?

CVE-2026-71291 is a high-severity code injection vulnerability in bolt core, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Bolt CMS renders content field values through Twig's full application-level Environment with no SandboxExtension registered anywhere in the codebase. In src/Entity/Field.php, getTwigValue calls shouldBeRenderedAsTwig, which gates rendering only on the field definition's allow_twig flag and a regex checking for , , or ; when true, the raw field value is compiled and rendered via with no sandboxing.

Weakness: CWE-1336 (Improper Neutralization of Special Elements Used in a Template Engine)

## Which versions are affected by CVE-2026-71291?


## How do I fix CVE-2026-71291?

No fix has been published for CVE-2026-71291 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71291 being exploited?

There is no known exploitation of CVE-2026-71291 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71291 and fix it if it is affected.

What it is: CVE-2026-71291 is a high-severity code injection vulnerability in bolt core, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-71291 in the wild and no public exploit code.

Affected product: bolt core. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-71291/ (Markdown: https://insights.sbomify.com/CVE-2026-71291/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71291
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71291
- OSV: https://osv.dev/vulnerability/CVE-2026-71291

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-71291/
Summaries are generated and may contain mistakes; the official description above is the record.