[IntelliJ] Uncaught Exception Error retrieving vulnerability data from GitHub Security Advisory API java.io.IOException: Tunnel failed, got: 403

IntelliJ build version: 2025.3.3 IU-253.31033.145
OS: Mac OS X
JDK: JetBrains s.r.o. 21.0.10
Plugin version: 3.97.3-2025.3
Additional Info: None
Parent component:

com.intellij.openapi.wm.impl.IdeRootPane[,0,0,1728x994,layout=com.intellij.openapi.wm.impl.IdeRootPane$CustomHeaderRootLayout,alignmentX=0.0,alignmentY=0.0,border=,flags=449,maximumSize=,minimumSize=,preferredSize=]

Error message:

IdeaLoggingEvent[message=Error retrieving vulnerability data from GitHub Security Advisory API, throwable=java.io.IOException: Tunnel failed, got: 403
	at <REDACTED: user-file-path>(HttpClientImpl.java:970)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.retrieveVulnerabilityData(CVECheckService.java:312)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.fetchCves(CVECheckService.java:241)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.getCveUpgradeIssues(CVECheckService.java:200)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.CVECheckService.batchGetCVEIssues(CVECheckService.java:171)
	at com.microsoft.azure.toolkit.intellij.appmod.javaupgrade.service.JavaUpgradeIssuesDetectionService.getCVEIssues(JavaUpgradeIssuesDetectionService.java:385

Start in CVECheckService.java at retrieveVulnerabilityData(), then follow fetchCves(), getCveUpgradeIssues(), and batchGetCVEIssues() in the stack trace. Reproduce the GitHub Security Advisory API request in the IntelliJ plugin environment, especially where the 403 tunnel failure occurs. Done means the vulnerability check no longer surfaces this uncaught exception.