● High · CVSS 8.6

How to Fix CVE-2026-28442: External control of file name or path in ZimaOS

Q: What is the CVSS score for CVE-2026-28442?

8.6 (High). Vector: `CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`.

Q: Where is the official advisory for CVE-2026-28442?

The vendor advisory is at [https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-q5hp-59wm-9xq3](https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-q5hp-59wm-9xq3). The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-28442.

By Sai Kiran Pandrala. Last verified: 2026-05-25.

CVE-2026-28442 is a external control of file name or path in IceWhaleTech ZimaOS. The fix is to apply the vendor patch noted below.

⚡ At a glance


Severity	8.6 (High)
Actively exploited?	No public listing in CISA KEV
Affected	ZimaOS = 1.5.2-beta3
Fixed in	See vendor advisory
Type (CWE)	CWE-73: External Control of File Name or Path

What is CVE-2026-28442?

ZimaOS is a fork of CasaOS, an operating system for Zima devices and x86-64 systems with UEFI. In version 1.5.2-beta3, users are restricted from deleting internal system files or folders through the application interface. However, when interacting directly with the API, these restrictions can be bypassed. By altering the path parameter in the delete request, internal OS files and directories can be removed successfully. The backend processes these manipulated requests without validating whether the targeted path belongs to restricted system locations. This demonstrates improper input validation and broken access control on sensitive filesystem operations. No known public patch is available. The CVSS base score is 8.6 (High), which puts this in the upper risk band and warrants a fast patch cycle. The official advisory is at https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-q5hp-59wm-9xq3.

Am I affected?

Check the version of ZimaOS you are running and compare it against the Affected row above (ZimaOS = 1.5.2-beta3). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


# Linux package check
dpkg -s zimaos 2>/dev/null | grep -i ^Version
rpm -q zimaos 2>/dev/null
command -v zimaos >/dev/null && zimaos --version 2>/dev/null


# Windows (PowerShell)
Get-Package -Name "*ZimaOS*" -ErrorAction SilentlyContinue | Select-Object Name, Version
winget list --name "ZimaOS" 2>$null

How to fix CVE-2026-28442

Upgrade ZimaOS to a patched build: See vendor advisory. The vendor advisory is the source of truth for the exact fixed version.

Ubuntu / Debian


sudo apt-get update
sudo apt-get install --only-upgrade zimaos
dpkg -s zimaos | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


sudo dnf upgrade --refresh zimaos -y
# or for older releases:
sudo yum update zimaos -y
rpm -q zimaos

SUSE / openSUSE


sudo zypper refresh
sudo zypper update zimaos
rpm -q zimaos

Complete PowerShell remediation script (Windows)


# Fix script for CVE-2026-28442 affecting ZimaOS
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-28442-fix-$(Get-Date -Format yyyyMMdd-HHmmss).log"
New-Item -ItemType Directory -Force (Split-Path $LogPath) | Out-Null
Start-Transcript -Path $LogPath -Append

try {
    Write-Host "[1/4] Detect installed version"
    $pkg = Get-Package -Name "*ZimaOS*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

    Write-Host "[2/4] Backup configuration"
    $backup = "C:\Backup\zimaos-$(Get-Date -Format yyyyMMdd)"
    New-Item -ItemType Directory -Force $backup | Out-Null
    Get-ChildItem "C:\ProgramData\ZimaOS" -ErrorAction SilentlyContinue |
        Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "ZimaOS" --silent --accept-source-agreements --accept-package-agreements
    if ($LASTEXITCODE -ne 0) {
        # Fallback: pull latest via OS update channel
        Install-Module -Name PSWindowsUpdate -Force -SkipPublisherCheck -ErrorAction SilentlyContinue
        Import-Module PSWindowsUpdate
        Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
    }

    Write-Host "[4/4] Verify the patched build"
    winget list --name "ZimaOS"
    Write-Host "Patch applied. Reboot if prompted."
    exit 0
} catch {
    Write-Error "Patch failed: $_"
    exit 1
} finally {
    Stop-Transcript
}

Complete Bash remediation script (Linux)


#!/usr/bin/env bash
# Fix script for CVE-2026-28442 affecting ZimaOS
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-28442-fix-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG") 2>&1

echo "[1/4] Detect installed version"
if command -v dpkg >/dev/null; then
    dpkg -s zimaos 2>/dev/null | grep -i ^Version || echo "zimaos not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q zimaos || echo "zimaos not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-28442-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/zimaos /etc/zimaos.d /etc/zimaos.conf; do
    [ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done

echo "[3/4] Apply the upgrade (target: See vendor advisory)"
if command -v apt-get >/dev/null; then
    apt-get update
    apt-get install --only-upgrade -y zimaos
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y zimaos
elif command -v yum >/dev/null; then
    yum update -y zimaos
elif command -v zypper >/dev/null; then
    zypper --non-interactive update zimaos
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s zimaos 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q zimaos
fi
echo "Done. Restart any service that loaded the old library."

If you can't patch immediately

Apply at least one of the following inline controls until you can deploy the patched build. None replace the upgrade.

Restrict exposure with nftables (Linux)


# Allow only trusted CIDR to reach the affected service ports
sudo nft add table inet filter 2>/dev/null || true
sudo nft 'add chain inet filter input { type filter hook input priority 0 ; }' 2>/dev/null || true
sudo nft 'add rule inet filter input tcp dport {80, 443} ip saddr != 10.0.0.0/8 drop'
sudo nft list ruleset

Block at the host firewall (Windows)


New-NetFirewallRule -DisplayName "Block-CVE-2026-28442" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-28442"

Disable the affected service (Linux)


sudo systemctl stop zimaos 2>/dev/null || true
sudo systemctl disable zimaos 2>/dev/null || true

If the vendor advisory lists an official workaround, prefer that wording verbatim. If no workaround is published, the only safe remediation is the patch.

How to verify the fix worked

After upgrading, confirm the installed version matches the patched build and that no old library is still loaded by a long-running process.


# Linux
dpkg -s zimaos 2>/dev/null | grep -i ^Version
rpm -q zimaos 2>/dev/null || true
# Pid map check for old library handles
sudo lsof +c0 2>/dev/null | grep -i "DEL.*lib" || true


# Windows
Get-Package -Name "*ZimaOS*" | Select-Object Name, Version
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected: the reported version is at or above See vendor advisory. Restart the affected service (systemctl restart <service> on Linux, or restart the Windows service) so it loads the patched binary.

Frequently asked questions

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Is CVE-2026-28442 actively exploited?

There is no public confirmation of exploitation in the wild listed in CISA KEV at the time of this writing. Patch anyway. Public exploits commonly follow disclosure within weeks.

Do I need to reboot after patching CVE-2026-28442?

For kernel and OS-level updates, yes. For most userland packages a systemctl restart <service> is enough on Linux, and restarting the Windows service or app on Windows. Any process that loaded the old library keeps using it until restarted.

What is the CVSS score for CVE-2026-28442?

8.6 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.

Where is the official advisory for CVE-2026-28442?

The vendor advisory is at https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-q5hp-59wm-9xq3. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-28442.

References

Official vendor advisory: https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-q5hp-59wm-9xq3
NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28442
CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

*Written by Sai Kiran Pandrala. Assembled from the official vendor advisory, NVD record, and CISA KEV listing on 2026-05-25. Always confirm against the vendor's advisory before applying changes in production.*