CVE-2026-45756 Symfony: JsonPath Evaluates Attacker-Controlled Regular Expressions in match()/search() Without Limits — ReDoS
Attackers can cause denial of service in Symfony JsonPath by submitting malicious regular expressions that trigger catastrophic backtracking.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45756?
CVE-2026-45756 is a high-severity denial of service vulnerability in Sensiolabs Symfony, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 7.3.0-BETA1 until 7.4.12 and 8.0.12, the JsonPath component compiles attacker-controlled match() and search() filter patterns directly into preg_match() without a length cap, i-regexp restriction, or bounded backtracking, allowing catastrophic-backtracking expressions to pin worker CPU and cause denial of service. This issue is fixed in versions 7.4.12 and 8.0.12.
Which versions are affected by CVE-2026-45756?
8 open source packages ship an affected version, including symfony/json-path and symfony/symfony. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
symfony/json-path Packagist | From 7.3.0 | 7.4.12 |
symfony/json-path Packagist | From 7.3.0 | 7.4.12 |
symfony/json-path Packagist | From 8.0.0 | 8.0.12 |
symfony/json-path Packagist | From 8.0.0 | 8.0.12 |
symfony/symfony Packagist | From 7.3.0 | 7.4.12 |
symfony/symfony Packagist | From 7.3.0 | 7.4.12 |
2 more packages
symfony/symfony Packagist | From 8.0.0 | 8.0.12 |
symfony/symfony Packagist | From 8.0.0 | 8.0.12 |
Products include Sensiolabs Symfony.
How do I fix CVE-2026-45756?
Upgrade symfony/json-path to a fixed version for your release line: 7.4.12 or 8.0.12.
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-2026-45756 being exploited?
There is no known exploitation of CVE-2026-45756 in the wild and no public exploit code.
Other vulnerabilities in Sensiolabs Symfony
Sources
Also known as DEBIAN-CVE-2026-45756, GHSA-8v8v-g73j-492j, UBUNTU-CVE-2026-45756.