CVE-2026-45776: OpenXDMoD SUPReMM Access Control Bypass – Patch to 11.0.3

Technical summary

CVE-2026-45776 stems from improper access control in OpenXDMoD's session variable handling. An attacker with valid credentials can craft a POST request to set a session variable that is later used in authorization decisions. The flaw is specifically triggered when the SUPReMM module is active. The resulting bypass is limited to unauthorized read access to job performance metrics; no data modification or system availability impact occurs. The vulnerability scored CVSS 4.3 (MEDIUM) under CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, reflecting the requirement for prior authentication and the confined scope of information disclosure.

Business impact

For research institutions and national labs relying on OpenXDMoD to track HPC resource usage, unauthorized visibility into job efficiency metrics can undermine user privacy and competitive advantage in research workflows. Users may be unaware their performance data is exposed to other authenticated users. No direct operational downtime or data destruction occurs, but data sensitivity in academic and scientific settings may trigger compliance or policy violations. Reputational impact depends on the sensitivity of workload data visible through the metrics.

Affected systems

All deployments of OpenXDMoD prior to version 11.0.3 are vulnerable if the optional Job Performance (SUPReMM) module is installed. Installations without SUPReMM are not impacted. The vulnerability affects the framework itself; impact scope is limited to authenticated users within an OpenXDMoD installation.

Exploitability

Exploitation requires an attacker to possess valid credentials to the OpenXDMoD instance—either a personal account or compromised user credentials. No authentication bypass is present; the flaw only affects authorization after login. The technical bar is low: an HTTP POST request with a crafted session variable. No user interaction, social engineering, or complex tooling is required. As of the published date (2026-06-05), no active exploitation in the wild has been reported.

Remediation

OpenXDMoD 11.0.3, released on 2026-05-12, patches the session variable handling and access control logic. Organizations must upgrade to this version or later. A manual patch option is documented by the vendor for environments where immediate version upgrades are not feasible; consult the OpenXDMoD advisory for backported patch details. After patching, affected users' historical data exposure cannot be reversed but future access is controlled.

Patch guidance

Upgrade OpenXDMoD to version 11.0.3 or later. Verify the SUPReMM module status in your deployment configuration; if not installed, the vulnerability does not apply but patching for general security posture remains recommended. Test the upgrade in a non-production environment first, as OpenXDMoD integrations with HPC schedulers may require configuration validation. Review any access logs between the initial CVE publication date (2026-04-06) and your patching date to identify suspicious session activity. The vendor's advisory should be consulted for specific upgrade procedures and any breaking changes.

Detection guidance

Monitor web server logs for POST requests to OpenXDMoD that attempt to set or modify session variables. Look for requests from authenticated users targeting administrative or configuration endpoints they don't typically access. If SUPReMM is enabled, audit access to job performance query endpoints and cross-reference with user role assignments. Application-level logging in OpenXDMoD (if enabled) should show unusual session state modifications. However, detection is challenging if logs are not retained; proactive patching is more reliable than reactive detection for this flaw.

Why prioritize this

Although the CVSS score is moderate (4.3), priority should be elevated for installations with sensitive research workloads or strict data governance requirements. The barrier to exploitation is low (valid credentials only), and the privacy implications for job metrics may exceed the raw severity score. Academic and national labs handling proprietary or classified computing tasks should treat this as high-priority. Commercial HPC centers with SLAs or regulatory obligations should patch within 30 days. Low-risk test or development deployments can be deprioritized but should not be ignored indefinitely.

Risk score, explained

The CVSS 4.3 MEDIUM score reflects: (1) Network attack vector (attacker can exploit remotely), (2) Low attack complexity (standard HTTP POST), (3) Low privileges required (authenticated user), (4) No user interaction needed, (5) Confidentiality impact limited to one user's unauthorized view of another's metrics, and (6) No integrity or availability impact. The score appropriately penalizes the authentication requirement and confined scope, but does not fully capture privacy risk in regulated or highly sensitive research environments. Organizations should consider contextual risk elevation based on data classification.

Frequently asked questions