CVE-2026-45090 affects Dalfox, an open-source XSS scanner, prior to version 2.13.0. The vulnerability exists in ParameterAnalysis where two sequential worker stages write to the same results channel. After the first stage closes the channel, the second stage attempts to write to the closed channel, causing a Go runtime panic that crashes the entire process. In server mode, this crash can be remotely triggered by unauthenticated attackers through the REST API when no API key is configured. The vulnerability is fixed in version 2.13.0.