● Medium · CVSS 5.3

How to Fix CVE-2026-3268: Improper access controls in PSI Probe

Q: What is the CVSS score for CVE-2026-3268?

5.3 (Medium). Vector: `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`.

Q: Where is the official advisory for CVE-2026-3268?

The vendor advisory is at [https://vuldb.com/?id.347992](https://vuldb.com/?id.347992). The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-3268.

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

CVE-2026-3268 is a improper access controls in psi-probe PSI Probe. The fix is to apply the vendor patch noted below.

⚡ At a glance


Severity	5.3 (Medium)
Actively exploited?	No public listing in CISA KEV
Affected	PSI Probe 5.0; PSI Probe 5.1; PSI Probe 5.2; PSI Probe 5.3.0
Fixed in	See vendor advisory
Type (CWE)	CWE-284: Improper Access Controls

What is CVE-2026-3268?

A vulnerability was detected in psi-probe PSI Probe up to 5.3.0. The affected element is an unknown function of the file psi-probe-core/src/main/java/psiprobe/controllers/sessions/RemoveSessAttributeController.java of the component Session Attribute Handler. Performing a manipulation results in improper access controls. The attack can be initiated remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way. The CVSS base score is 5.3 (Medium). The official advisory is at https://vuldb.com/?id.347992.

Am I affected?

Check the version of PSI Probe you are running and compare it against the Affected row above (PSI Probe 5.0; PSI Probe 5.1; PSI Probe 5.2; PSI Probe 5.3.0). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


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


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

How to fix CVE-2026-3268

Upgrade PSI Probe 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 psi-probe
dpkg -s psi-probe | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


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

SUSE / openSUSE


sudo zypper refresh
sudo zypper update psi-probe
rpm -q psi-probe

Node.js / npm


# Update the affected package in your project
npm install PSI Probe@latest
npm ls PSI Probe
npm audit fix

Complete PowerShell remediation script (Windows)


# Fix script for CVE-2026-3268 affecting PSI Probe
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-3268-fix-$(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"
    $pkg = Get-Package -Name "*PSI Probe*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

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

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "PSI Probe" --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 "PSI Probe"
    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-2026-3268 affecting PSI Probe
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-3268-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 psi-probe 2>/dev/null | grep -i ^Version || echo "psi-probe not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q psi-probe || echo "psi-probe not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-3268-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/psi-probe /etc/psi-probe.d /etc/psi-probe.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 psi-probe
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y psi-probe
elif command -v yum >/dev/null; then
    yum update -y psi-probe
elif command -v zypper >/dev/null; then
    zypper --non-interactive update psi-probe
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s psi-probe 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q psi-probe
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-2026-3268" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-3268"

Disable the affected service (Linux)


sudo systemctl stop psi-probe 2>/dev/null || true
sudo systemctl disable psi-probe 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 psi-probe 2>/dev/null | grep -i ^Version
rpm -q psi-probe 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 "*PSI Probe*" | 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

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

How to Fix CVE-2026-24819: Path Traversal in weixin4j — Path Traversal in weixin4j
How to Fix CVE-2026-4681: Deserialization RCE in Windchill PDMLink — Deserialization RCE in Windchill PDMLink
How to Fix CVE-2026-3611: Honeywell IQ4x BMS Controller Missing authentication for critical function , Honeywell IQ4x BMS Controller Missing authentication for critical function
How to Fix CVE-2026-27815: Command Injection in everest-core , Command Injection in everest-core
How to Fix CVE-2026-24055: Access Control Bypass in langfuse , Access Control Bypass in langfuse

Is CVE-2026-3268 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-2026-3268?

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-2026-3268?

5.3 (Medium). Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P.

Where is the official advisory for CVE-2026-3268?

The vendor advisory is at https://vuldb.com/?id.347992. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-3268.

References

Official vendor advisory: https://vuldb.com/?id.347992
NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3268
CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Additional reference: https://vuldb.com/?ctiid.347992
Additional reference: https://vuldb.com/?submit.758664
Additional reference: https://github.com/AnalogyC0de/public_exp/issues/14

*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.*