CVE-2026-7254: IBM OpenBMC DoS Vulnerability

CVE-2026-7254 Overview

CVE-2026-7254 affects IBM OpenBMC firmware versions FW1110.00 through FW1110.11. The vulnerability allows unauthenticated remote attackers to trigger denial of service conditions over the network. OpenBMC is an open-source baseboard management controller (BMC) firmware stack used to manage server hardware out-of-band.

The weakness is categorized under [CWE-1284] (Improper Validation of Specified Quantity in Input). Successful exploitation degrades availability of management functions on affected IBM hardware. An attacker does not need credentials or user interaction to exploit the flaw.

Critical Impact

Unauthenticated network attackers can disrupt BMC availability, impairing out-of-band server management on IBM OpenBMC FW1110.00 through FW1110.11.

Affected Products

• IBM OpenBMC firmware FW1110.00
• IBM OpenBMC firmware versions through FW1110.11
• IBM server platforms running affected OpenBMC builds

Discovery Timeline

• 2026-05-27 - CVE-2026-7254 published to NVD
• 2026-05-27 - Last updated in NVD database

Technical Details for CVE-2026-7254

Vulnerability Analysis

CVE-2026-7254 is a denial of service vulnerability in IBM OpenBMC firmware. The flaw resides in network-facing management services exposed by the BMC. An unauthenticated attacker sends crafted network traffic to the BMC interface and disrupts its normal operation.

OpenBMC provides remote management capabilities including IPMI, Redfish, and SSH services. A successful attack affects only availability. Confidentiality and integrity of managed data remain intact, but administrators lose remote visibility and control over affected hardware while the BMC is degraded.

The vulnerability is mapped to [CWE-1284], indicating the firmware fails to properly validate the quantity of input it receives. This category typically covers missing length checks, count validation gaps, or boundary enforcement failures in input handling routines.

Root Cause

The root cause is improper validation of specified quantity in input ([CWE-1284]). The OpenBMC firmware accepts network input without enforcing constraints on the size or count of supplied data elements. When the firmware processes oversized or unexpected input volumes, internal resource handling fails and the management service becomes unresponsive.

Attack Vector

The attack vector is network-based with low complexity. An attacker requires no privileges and no user interaction. The attacker sends specifically crafted packets to a network-reachable OpenBMC interface and triggers the denial of service condition.

BMC interfaces are typically deployed on dedicated management networks. Organizations that expose BMC interfaces to broader networks or the internet face elevated risk. Refer to the IBM Support Page for vendor technical details.

Detection Methods for CVE-2026-7254

Indicators of Compromise

• Unexpected loss of connectivity to BMC management interfaces (IPMI, Redfish, SSH, or web UI)
• Repeated BMC service restarts or watchdog resets logged on affected hardware
• Anomalous inbound traffic patterns to BMC management IP addresses from untrusted sources

Detection Strategies

• Monitor BMC service health via Redfish ServiceRoot endpoint polling and alert on response failures
• Inspect network flow logs for unusual request volumes or malformed protocol traffic targeting BMC IPs
• Correlate hardware management alerts with network telemetry to identify denial of service patterns

Monitoring Recommendations

• Enable centralized logging from OpenBMC instances and forward events to a SIEM for correlation
• Track BMC firmware version inventory to identify systems running FW1110.00 through FW1110.11
• Baseline normal BMC management traffic volumes and alert on deviations

How to Mitigate CVE-2026-7254

Immediate Actions Required

• Identify all IBM servers running OpenBMC firmware versions FW1110.00 through FW1110.11
• Restrict network access to BMC management interfaces to dedicated, isolated management networks
• Apply the IBM firmware update referenced in the vendor advisory as soon as it is available

Patch Information

IBM has published vendor guidance for CVE-2026-7254. Review the IBM Support Page for the affected firmware list, fixed versions, and update procedures. Schedule firmware updates during maintenance windows since BMC updates may require server reboots or power cycling.

Workarounds

• Place BMC interfaces on isolated VLANs with strict access control lists permitting only authorized administrator workstations
• Disable unused management protocols on the BMC to reduce attack surface
• Apply firewall rules at the network edge to block external traffic to BMC management ports

# Example: restrict BMC management access at the network layer
# Replace placeholders with actual BMC and management subnet addresses
iptables -A FORWARD -s <mgmt_admin_subnet> -d <bmc_ip> -j ACCEPT
iptables -A FORWARD -d <bmc_ip> -j DROP