CVE-2026-54728: bunkerweb: Improper Input Validation and Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') in BunkerWeb

Vulnerability summary

CVE-2026-54728 is a medium (CVSS 6.1) Improper Input Validation vulnerability in bunkerity bunkerweb. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 32.2% of scored vulnerabilities.

Timeline

1. 16-07-2026
   PublishedVulnerability first disclosed.
2. 17-07-2026
   Last modifiedVulnerability information updated.

Description

bunkerweb is an Open-source and next-generation Web Application Firewall (WAF). Prior to BunkerWeb 1.6.12 and BunkerWeb PRO 0.57, authenticated Host header handling in the BunkerWeb UI and API improperly validated and neutralized user-controlled input in a configuration-dependent path, allowing a low-privileged authenticated user to escalate privileges and affect confidentiality, integrity, and availability of the BunkerWeb instance. This issue is fixed in BunkerWeb version 1.6.12 and BunkerWeb PRO version 0.57.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream ComponentThe product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.