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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2026-57584?
2 open source packages ship an affected version, including phalcon/cphalcon.
| Package | 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.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-57584 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57584 exists.
Sources
Also known as GHSA-x7rj-f32v-7jjg.