# CVE-2026-112777: Craft CMS before 4.18.8 and 5.11.0 Twig create() Blocklist Bypass Leading to RCE

> Craft CMS administrators can bypass Twig blocklists to execute remote code or read secrets via case-sensitive class name checks.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** GHSA-f7pv-pv9r-vg93, GHSA-w643-x88w-6wcm

## What is CVE-2026-112777?

CVE-2026-112777 is a high-severity code injection vulnerability in craftcms cms, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Craft CMS 4.x before 4.18.8 and 5.x before 5.11.0 contains a blocklist bypass in the Twig create() function because its class-name checks are case-sensitive while PHP class resolution is not. Attackers with template-execution rights, such as Control Panel administrators, can instantiate SplFileObject via a lowercase class name to read .env secrets or write a PHP file into the webroot for remote code execution.

Weakness: CWE-184 (Incomplete List of Disallowed Inputs)

## Which versions are affected by CVE-2026-112777?


## How do I fix CVE-2026-112777?

No fix has been published for CVE-2026-112777 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-112777 being exploited?

There is no known exploitation of CVE-2026-112777 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-112777 and fix it if it is affected.

What it is: CVE-2026-112777 is a high-severity code injection vulnerability in craftcms cms, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-112777 in the wild and no public exploit code.

Affected product: craftcms cms. 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-2026-112777/ (Markdown: https://insights.sbomify.com/CVE-2026-112777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-112777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-112777
- OSV: https://osv.dev/vulnerability/CVE-2026-112777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-112777/
Summaries are generated and may contain mistakes; the official description above is the record.