SB2026071457 - Inefficient regular expression complexity in FHIR

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Main Vulnerability Database SB2026071457

SB2026071457 - Inefficient regular expression complexity in FHIR

Published: July 14, 2026

Security Bulletin ID SB2026071457
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Inefficient regular expression complexity (CVE-ID: CVE-2026-45367)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: 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]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient regular expression complexity in FHIRPathEngine matches(), matchesFull(), and replaceMatches() processing when evaluating user-supplied FHIRPath expressions containing crafted regular expressions. A remote attacker can send a crafted resource containing an evil regex pattern to cause a denial of service.

The issue affects the FHIR Validator HTTP endpoint, and no timeout mechanism protects FHIRPath evaluation in this code path.


Remediation

Install update from vendor's website.

References