# CVE-2026-62237: Grav < 2.0.4 ReDoS via regex_replace in Sandbox

> An authenticated page editor can cause denial of service via catastrophic regex backtracking in Grav CMS when Twig content processing is enabled.

- **Severity:** Medium 6.0 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **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:** 17 Jul 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-6gqg-9qjp-56jm

## What is CVE-2026-62237?

CVE-2026-62237 is a medium-severity denial of service vulnerability in getgrav grav, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Grav before 2.0.4 contains a regular expression denial of service (ReDoS) vulnerability in the regex_replace filter and function, which are allowlisted in the Twig content sandbox. When Twig processing in page content is enabled (security.twig_content.process_enabled: true, disabled by default), an authenticated page editor can supply a catastrophically backtracking PCRE pattern that is passed directly to PHP's preg_replace(), causing unbounded CPU consumption and denial of service to the web server process.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-62237?


## How do I fix CVE-2026-62237?

No fix has been published for CVE-2026-62237 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-62237 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-62237 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-62237 and fix it if it is affected.

What it is: CVE-2026-62237 is a medium-severity denial of service vulnerability in getgrav grav, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-62237 exists.

Affected product: getgrav grav. 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-2026-62237/ (Markdown: https://insights.sbomify.com/CVE-2026-62237/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-62237
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62237
- OSV: https://osv.dev/vulnerability/CVE-2026-62237

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-62237/
Summaries are generated and may contain mistakes; the official description above is the record.