# CVE-2026-57584: Phalcon: Catastrophic backtracking (ReDoS) in the default Phalcon Router route lead to remote unauthenticated DoS

> An attacker can cause remote denial of service via CPU exhaustion by sending crafted requests to Phalcon MVC applications using the default router.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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:** Yes
- **Published:** 10 Jul 2026
- **Updated:** 13 Jul 2026
- **Also known as:** GHSA-x7rj-f32v-7jjg

## What is CVE-2026-57584?

CVE-2026-57584 is a high-severity denial of service vulnerability in cphalcon, published on 10 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Phalcon is a high-performance, full-stack PHP framework. Prior to 5.15.0, every Phalcon MVC application built with a default router registers a built-in route whose compiled PCRE pattern contains the nested quantifier (/.), and the same construct is produced by the /:params placeholder and the CLI router. Phalcon\Mvc\Router::handle() matches this pattern against the attacker-controlled request URI on every request, so a crafted path such as one containing repeated slashes followed by decoded newlines can trigger catastrophic backtracking and cause CPU exhaustion or route-matching failure. This issue is fixed in version 5.15.0.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-57584?

2 open source packages ship an affected version, including phalcon/cphalcon.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `phalcon/cphalcon` | Packagist | All versions | 5.15.0 |
| `phalcon/cphalcon` | Packagist | All versions | 5.15.0 |

## How do I fix CVE-2026-57584?

Upgrade phalcon/cphalcon to 5.15.0 or later.

## Is CVE-2026-57584 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57584 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57584 and fix it if it is affected.

What it is: CVE-2026-57584 is a high-severity denial of service vulnerability in cphalcon, published on 10 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57584 exists.

Affected packages and fixed versions:
- phalcon/cphalcon (Packagist): affected all versions; fixed in 5.15.0
- phalcon/cphalcon (Packagist): affected all versions; fixed in 5.15.0

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-2026-57584/ (Markdown: https://insights.sbomify.com/CVE-2026-57584/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57584
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57584
- OSV: https://osv.dev/vulnerability/CVE-2026-57584

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57584/
Summaries are generated and may contain mistakes; the official description above is the record.