# CVE-2026-28783: Craft has a Twig Function Blocklist Bypass > Attackers with admin access or specific permissions can bypass Twig function blocklists to execute arbitrary code, read files, or perform SSRF attacks. - **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Mar 2026 - **Updated:** 6 Mar 2026 - **Also known as:** GHSA-5fvc-7894-ghp4 ## What is CVE-2026-28783? CVE-2026-28783 is a critical code injection vulnerability in Craftcms Craft Cms, published on 4 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim. ### Official description Craft is a content management system (CMS). Prior to 5.9.0-beta.1 and 4.17.0-beta.1, Craft CMS implements a blocklist to prevent potentially dangerous PHP functions from being called via Twig non-Closure arrow functions. In order to be able to successfully execute this attack, you need to either have allowAdminChanges enabled on production, or a compromised admin account, or an account with access to the System Messages utility. Several PHP functions are not included in the blocklist, which could allow malicious actors with the required permissions to execute various types of payloads, including RCEs, arbitrary file reads, SSRFs, and SSTIs. This vulnerability is fixed in 5.9.0-beta.1 and 4.17.0-beta.1. Weakness: CWE-94 (Improper Control of Generation of Code), CWE-184 (Incomplete List of Disallowed Inputs), CWE-1336 (Improper Neutralization of Special Elements Used in a Template Engine) ## Which versions are affected by CVE-2026-28783? 4 open source packages ship an affected version, including craftcms/cms. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `craftcms/cms` | Packagist | From 4.0.0-RC1 | 4.17.0-beta.1 | | `craftcms/cms` | Packagist | From 4.0.0-RC1 | 4.17.0-beta.1 | | `craftcms/cms` | Packagist | From 5.0.0-RC1 | 5.9.0-beta.1 | | `craftcms/cms` | Packagist | From 5.0.0-RC1 | 5.9.0-beta.1 | Products: Craftcms Craft Cms. ## How do I fix CVE-2026-28783? Upgrade craftcms/cms to a fixed version for your release line: 4.17.0-beta.1 or 5.9.0-beta.1. ## Is CVE-2026-28783 being exploited? There is no known exploitation of CVE-2026-28783 in the wild and no public exploit code. ## Other vulnerabilities in Craftcms Craft Cms - [CVE-2025-32432](https://insights.sbomify.com/CVE-2025-32432/): Craft CMS Code Injection (critical 10.0, exploited in the wild) - [CVE-2024-56145](https://insights.sbomify.com/CVE-2024-56145/): Craft CMS Code Injection (critical 9.3, exploited in the wild) - [CVE-2025-23209](https://insights.sbomify.com/CVE-2025-23209/): Craft CMS Code Injection (high 8.1, exploited in the wild) - [CVE-2025-35939](https://insights.sbomify.com/CVE-2025-35939/): Craft CMS External Control of Assumed-Immutable Web Parameter (medium 6.9, exploited in the wild) - [CVE-2023-41892](https://insights.sbomify.com/CVE-2023-41892/): Craft CMS Remote Code Execution vulnerability (critical 10.0) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-28783 and fix it if it is affected. What it is: CVE-2026-28783 is a critical code injection vulnerability in Craftcms Craft Cms, published on 4 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-28783 in the wild and no public exploit code. Affected packages and fixed versions: - craftcms/cms (Packagist): affected from 4.0.0-RC1; fixed in 4.17.0-beta.1 - craftcms/cms (Packagist): affected from 4.0.0-RC1; fixed in 4.17.0-beta.1 - craftcms/cms (Packagist): affected from 5.0.0-RC1; fixed in 5.9.0-beta.1 - craftcms/cms (Packagist): affected from 5.0.0-RC1; fixed in 5.9.0-beta.1 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-2026-28783/ (Markdown: https://insights.sbomify.com/CVE-2026-28783/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28783 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28783 - OSV: https://osv.dev/vulnerability/CVE-2026-28783 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-28783/ Summaries are generated and may contain mistakes; the official description above is the record.