CVE-2026-12974: Forcepoint NGFW Security Policy Bypass

CVE-2026-12974 Overview

CVE-2026-12974 is a Security Policy Bypass vulnerability in the Forcepoint Security Engine (Next-Generation Firewall). The flaw allows a network-based attacker to circumvent enforced security policies without authentication or user interaction. Because the NGFW acts as a control point for segmented networks, a bypass exposes downstream systems, data flows, and trust boundaries protected by the appliance. The weakness is classified under [CWE-183: Permissive List of Allowed Inputs], indicating that the engine treats certain traffic as permitted when it should be denied.

Critical Impact
Attackers can bypass NGFW policy enforcement over the network with no authentication, undermining segmentation and confidentiality, integrity, and availability of downstream systems.

Affected Products

Forcepoint Security Engine (NGFW) versions 7.1.0 through 7.1.13
Forcepoint Security Engine (NGFW) versions 7.3.0 through 7.3.1, and 7.3.3
Forcepoint Security Engine (NGFW) versions 7.4.0 through 7.4.1, and 7.5.0

Discovery Timeline

2026-09-23 - CVE-2026-12974 published to the National Vulnerability Database
2026-09-23 - Last updated in NVD database

Technical Details for CVE-2026-12974

Vulnerability Analysis

The Forcepoint Security Engine enforces policy decisions on traffic traversing the NGFW. CVE-2026-12974 breaks that enforcement path, allowing traffic that should be blocked to pass through. The advisory categorizes the issue as a Security Policy Bypass affecting multiple release trains between 7.1.x and 7.5.0.

The vulnerability is network-reachable and requires no privileges or user interaction. Successful exploitation does not directly compromise the NGFW's own confidentiality, integrity, or availability. Instead, the impact falls on subsequent systems the firewall was configured to protect, where confidentiality, integrity, and availability can all be affected.

Refer to the Forcepoint Security Advisory CVE-2026-12974 for the authoritative technical description.

Root Cause

The underlying weakness is [CWE-183: Permissive List of Allowed Inputs]. The engine's input evaluation logic permits inputs or traffic conditions that should be excluded by the configured policy. When those conditions are met, the decision engine returns an allow verdict where a deny was intended.

Attack Vector

An unauthenticated remote attacker sends traffic crafted to trigger the permissive evaluation path. The NGFW forwards the traffic instead of dropping or inspecting it against the intended rule. No credentials, user interaction, or prior foothold is required.

No public exploit code or proof-of-concept has been published. Technical details of the trigger conditions are not disclosed in the advisory.

Detection Methods for CVE-2026-12974

Indicators of Compromise

Traffic observed on internal segments that violates documented NGFW policy, especially between zones that should be strictly segmented.
Session logs on the Forcepoint NGFW showing allow decisions for source, destination, or protocol combinations that are explicitly denied by rule.
Flow records from downstream sensors that contradict expected firewall drop counts for the same five-tuples.

Detection Strategies

Perform periodic policy validation by generating known-bad test flows from outside the trust boundary and confirming the NGFW blocks them.
Correlate NGFW decision logs with NetFlow, IPFIX, or switch SPAN data to identify allowed traffic that should have been dropped.
Alert on unexpected east-west or north-south flows crossing zones that the NGFW policy prohibits.

Monitoring Recommendations

Forward Forcepoint NGFW logs to a centralized analytics platform and baseline expected allow and deny ratios per rule.
Monitor for policy engine errors, rule evaluation warnings, or version strings matching affected releases (7.1.0-7.1.13, 7.3.0-7.3.1, 7.3.3, 7.4.0-7.4.1, 7.5.0).
Track authentication and administrative changes on the Security Management Center to rule out attacker-driven policy modification.

How to Mitigate CVE-2026-12974

Immediate Actions Required

Inventory all Forcepoint Security Engine (NGFW) appliances and identify those running the affected 7.1.x, 7.3.x, 7.4.x, or 7.5.0 versions.
Apply the fixed release identified in the Forcepoint Security Advisory CVE-2026-12974 as soon as an appropriate maintenance window is available.
Review recent firewall logs for evidence of unexpected allow decisions that could indicate prior exploitation.

Patch Information

Forcepoint has published guidance and fixed versions in the vendor advisory. Consult the Forcepoint Security Advisory CVE-2026-12974 for the specific patched builds that correspond to each affected branch and follow Forcepoint's documented upgrade procedure.

Workarounds

Add compensating controls upstream or downstream of the affected NGFW, such as a secondary firewall or IPS enforcing the same policy.
Tighten segmentation on adjacent switches and routers using access control lists to reduce the blast radius of any bypassed flow.
Restrict management and data-plane exposure of the NGFW to trusted networks until the patched version is deployed.

bash

# Example: verify running Forcepoint NGFW engine version and confirm it is not in the affected range
# Run from the NGFW command line
sg-status | grep -i version

# Example compensating ACL on an upstream router (Cisco IOS syntax)
# Deny traffic that must never traverse the segment protected by the NGFW
access-list 150 deny tcp any 10.10.0.0 0.0.255.255 eq 445
access-list 150 permit ip any any
interface GigabitEthernet0/1
 in access-list 150