PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-45756 Sensiolabs CVE debrief

CVE-2026-45756 is a high-severity denial-of-service vulnerability in the Symfony PHP framework. The vulnerability exists in the JsonPath component, where attacker-controlled match() and search() filter patterns are compiled directly into preg_match() without proper restrictions, allowing for catastrophic backtracking expressions that can pin worker CPU. This issue affects Symfony versions 7.3.0-BETA1 through 7.4.12 and 8.0.12. The vulnerability is patched in Symfony versions 7.4.12 and 8.0.12.

Vendor
Sensiolabs
Product
Symfony
CVSS
HIGH 8.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-21
Advisory published
2026-07-14
Advisory updated
2026-07-21

Who should care

Developers and administrators using Symfony versions 7.3.0-BETA1 through 7.4.11 or 8.0.0 through 8.0.11 should prioritize patching to prevent potential denial-of-service attacks. This includes operators managing affected deployments, platform administrators ensuring patch compliance, vulnerability management teams assessing exposure, and security teams verifying defensive measures.

Technical summary

The JsonPath component in Symfony, a PHP framework, is vulnerable to a denial-of-service attack due to improper handling of attacker-controlled match() and search() filter patterns. These patterns are directly compiled into preg_match() without a length cap, i-regexp restriction, or bounded backtracking. This allows for catastrophic-backtracking expressions that can consume excessive CPU resources, leading to a denial-of-service condition. The vulnerability affects Symfony versions from 7.3.0-BETA1 up to but not including 7.4.12 and 8.0.12. The issue is addressed in Symfony versions 7.4.12 and 8.0.12 through a patch that properly restricts the compilation of these patterns.

Defensive priority

High

Recommended defensive actions

  • Apply patches: Upgrade to Symfony version 7.4.12 or 8.0.12, or later, to apply the fix.
  • Inventory and triage: Identify and assess the risk of affected Symfony installations.
  • Monitoring: Implement monitoring to detect potential exploitation attempts.
  • Exception tracking: Establish exception tracking to identify and address any issues related to the patched vulnerability.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record was published on 2026-07-14T18:17:17.563Z and was last modified on 2026-07-21T19:17:10.237Z. The NVD entry is currently Analyzed. The vulnerability is caused by the JsonPath component compiling attacker-controlled patterns into preg_match() without restrictions, allowing for catastrophic backtracking.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-14T18:17:17.563Z and has not been modified since then. The NVD entry is currently Analyzed.