⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 8.8

How to Fix CVE-2026-1618: Authentication Bypass in FlexCity/Kiosk

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 8.8 - High
Actively exploited?Not currently listed in CISA KEV
Affected1.0 < 1.0.36
Fixed inSee vendor advisory
Type (CWE)CWE-288: Authentication Bypass Using an Alternate Path or Channel

What is CVE-2026-1618?

CVE-2026-1618 is an authentication bypass in FlexCity/Kiosk. A flaw in the authentication or session-handling logic lets a remote attacker reach administrative functions without valid credentials. In several reported cases this leads directly to remote code execution. Vendor description: Authentication Bypass Using an Alternate Path or Channel vulnerability in Universal Software Inc. FlexCity/Kiosk allows Privilege Escalation.This issue affects FlexCity/Kiosk: from 1.0 before 1.0.36.

Why this CVE matters

Authentication bypass on a network appliance or admin console is a top-tier target. Once the attacker is past the login, every administrative endpoint becomes available, including the ones that change settings, upload firmware, or run shell commands.

For deployments of FlexCity/Kiosk that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Open FlexCity/Kiosk's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-1618

The fix is to upgrade FlexCity/Kiosk to version 1.0.36 or later.

Affected versions confirmed in the CVE record:

Apply the iOS / iPadOS update


<!-- enrich_agent_2:v1 -->
# Check the current iOS build (libimobiledevice).
ideviceinfo -k ProductVersion
ideviceinfo -k BuildVersion

# Trigger the update via Settings -> General -> Software Update on-device.


<!-- enrich_agent_2:v1 -->
# Fleet check: find devices still on a pre-patch build (Intune example).
Connect-MgGraph -Scopes Device.Read.All
Get-MgDeviceManagementManagedDevice -Filter "operatingSystem eq 'iOS'" |
  Select-Object DeviceName, OSVersion, UserPrincipalName

Verify the fix worked


<!-- enrich_agent_2:v1 -->
# 1. Confirm the running version matches the fixed-in version from the advisory.
#    Cross-check against the vendor advisory: https://www.usom.gov.tr/bildirim/tr-26-0065

# 2. Re-scan with your vulnerability scanner. The scanner should no longer flag
#    this CVE on the patched host.
# Example with Nmap NSE:
nmap -sV --script vuln <target-host>

# 3. Inspect the service / kernel logs for crash-loops or rollback events in
#    the first hour after the upgrade.
journalctl -u <service-name> --since "1 hour ago"
dmesg --since "1 hour ago"

If you cannot patch immediately

Restrict access to the affected administrative interface to trusted internal networks. Disable the vulnerable component if the vendor documents that as an interim option. Patch immediately when feasible.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for unexpected administrator accounts in FlexCity/Kiosk, scheduled tasks or cron jobs you did not create, new files in web-accessible directories, and outbound connections to addresses not in your baseline. Suspicious requests to the vulnerable endpoint immediately followed by successful 200-class responses with unusually large bodies are a strong indicator of exploitation.

Frequently asked questions

Is CVE-2026-1618 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-1618?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

Do I need to assume compromise if my FlexCity/Kiosk was internet-facing and unpatched?

For an unauthenticated RCE-class flaw exposed to the public internet during the known exploitation window, yes. Review logs, rotate credentials the process could access, and look for unexpected accounts, scheduled tasks, or outbound connections.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*