CVE-2026-7868 Overview
CVE-2026-7868 is an authorization flaw in IBM OpenBMC firmware. The vulnerability allows accounts with ReadOnly privileges to escalate themselves to administrator privileges. Affected releases include FW1110.00 through FW1110.20 and FW1060.00 through FW1060.71. The defect maps to CWE-863: Incorrect Authorization and is exploitable over the network by an authenticated low-privilege user. Successful exploitation grants full administrative control of the Baseboard Management Controller (BMC), which manages out-of-band server operations. See the IBM Support Page for vendor details.
Critical Impact
A ReadOnly BMC user can grant themselves administrator rights, gaining out-of-band control over server power, firmware, and console operations.
Affected Products
- IBM OpenBMC firmware FW1110.00 through FW1110.20
- IBM OpenBMC firmware FW1060.00 through FW1060.71
- IBM Power systems running affected OpenBMC releases
Discovery Timeline
- 2026-07-28 - CVE-2026-7868 published to NVD
- 2026-07-28 - Last updated in NVD database
Technical Details for CVE-2026-7868
Vulnerability Analysis
OpenBMC is IBM's Linux-based firmware stack for Baseboard Management Controllers. The BMC exposes management functions through a Redfish-compatible REST API and Web UI. The platform defines role-based access levels, with ReadOnly intended to permit only observation of system state.
CVE-2026-7868 breaks that role model. An authenticated ReadOnly user can issue requests that modify their own account role, promoting the account to administrator. Once elevated, the attacker can change firmware, reset host power, mount virtual media, and access the host serial console. This vertical privilege escalation defeats the separation between auditors and operators.
The vulnerability requires only low-privilege network access, no user interaction, and low attack complexity. Impact is limited to integrity, but integrity compromise at the BMC layer effectively yields full platform control.
Root Cause
The root cause is incorrect authorization ([CWE-863]) in the account management path. The affected code does not enforce that role-modification requests originate from a user holding a role with sufficient privilege. As a result, a ReadOnly session can execute privileged administrative operations on account objects.
Attack Vector
Exploitation requires valid credentials for any ReadOnly account. The attacker authenticates to the BMC management interface over the network and submits a role-change request against their own account. No social engineering, chained bug, or memory corruption primitive is needed. Technical details are described in the IBM Support advisory.
No public proof-of-concept or exploit code has been published for CVE-2026-7868 at the time of writing.
Detection Methods for CVE-2026-7868
Indicators of Compromise
- Redfish or REST API requests targeting /redfish/v1/AccountService/Accounts/ that modify the RoleId field, especially originating from accounts previously assigned ReadOnly.
- BMC audit log entries showing a role transition from ReadOnly to Administrator without a corresponding change-management ticket.
- New privileged sessions from source addresses that historically only performed GET requests.
Detection Strategies
- Correlate BMC authentication logs with account role changes and alert when the acting user's role is ReadOnly at request time.
- Baseline expected administrator accounts and flag any newly created or newly elevated administrators on OpenBMC endpoints.
- Monitor Redfish PATCH requests to AccountService resources and compare acting principal against required role.
Monitoring Recommendations
- Forward BMC syslog and Redfish event streams to a centralized SIEM for retention and correlation.
- Alert on firmware update, virtual media mount, and host power-control actions triggered shortly after any role change.
- Track outbound connections from BMC management VLANs, which should be minimal in normal operation.
How to Mitigate CVE-2026-7868
Immediate Actions Required
- Inventory all IBM Power systems and identify BMCs running OpenBMC FW1110.00–FW1110.20 or FW1060.00–FW1060.71.
- Restrict BMC management interfaces to a dedicated, isolated management VLAN with strict ACLs.
- Audit existing accounts, remove unused ReadOnly users, and rotate credentials for any account whose password may be shared or weak.
- Review BMC audit logs for unexpected role escalations across the affected firmware window.
Patch Information
Apply the fixed firmware releases identified on the IBM Support Page. Administrators should upgrade past FW1110.20 and FW1060.71 to the vendor-designated remediated versions. Validate firmware signatures after installation and reboot the BMC to load the new image.
Workarounds
- Disable or delete ReadOnly accounts on affected BMCs until firmware is patched.
- Enforce network segmentation so only trusted administrative hosts can reach the BMC Redfish and Web UI endpoints.
- Require multi-factor authentication on the jump hosts used to access BMC management networks.
- Increase logging verbosity on AccountService operations to capture forensic evidence of any exploitation attempt.
# Example: restrict BMC management access with host firewall rules
# Allow only the management jump host to reach BMC HTTPS/Redfish
iptables -A INPUT -p tcp --dport 443 -s 10.10.20.5 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
# List and remove unused ReadOnly accounts via Redfish
curl -k -u admin:'REPLACE' https://bmc.example.local/redfish/v1/AccountService/Accounts
curl -k -u admin:'REPLACE' -X DELETE \
https://bmc.example.local/redfish/v1/AccountService/Accounts/readonly_user
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
