CVE-2026-45777: Buffalo Open XDMoD RCE Vulnerability

CVE-2026-45777 Overview

Open XDMoD is an open framework for collecting and analyzing High Performance Computing (HPC) metrics. CVE-2026-45777 is a command injection vulnerability (CWE-78) that allows unauthenticated attackers to execute arbitrary system commands on the web server hosting Open XDMoD. The flaw affects versions 9.5.0 through 11.0.2 inclusive. Successful exploitation grants attackers the privileges of the web server process, enabling them to read or modify application data, alter system configuration, or disrupt service availability. The maintainers patched the issue in Open XDMoD 11.0.3 on May 12, 2026.

Critical Impact
Unauthenticated remote attackers can execute arbitrary commands on Open XDMoD web servers without user interaction, leading to full compromise of HPC analytics infrastructure.

Affected Products

Open XDMoD 9.5.0 through 11.0.2 (inclusive)
Open XDMoD deployments hosting HPC analytics workloads
Web servers running unpatched Open XDMoD instances

Discovery Timeline

2026-04-06 - Vulnerability reported privately to the Open XDMoD maintainers
2026-05-12 - Open XDMoD 11.0.3 released with patch for CVE-2026-45777
2026-06-05 - CVE-2026-45777 published to NVD
2026-06-10 - Last updated in NVD database

Technical Details for CVE-2026-45777

Vulnerability Analysis

CVE-2026-45777 is an OS command injection flaw classified under CWE-78. The vulnerability resides in Open XDMoD's web-facing components, where user-supplied input reaches a system command execution context without adequate sanitization. An attacker can craft a malicious HTTP request that injects shell metacharacters or additional commands into the underlying process invocation.

The vulnerability requires no authentication and no user interaction, making it exploitable by any network-adjacent attacker who can reach the Open XDMoD web interface. Open XDMoD is typically deployed within HPC environments at universities, national laboratories, and research institutions, where it aggregates job, performance, and accounting metrics across compute clusters.

Root Cause

The root cause is insufficient validation and sanitization of untrusted input passed to operating system command invocations. When the application constructs shell commands using attacker-controlled data, embedded metacharacters such as ;, |, &, or backticks allow command separation and chaining. The maintainers addressed the issue in version 11.0.3 and published a backport patch at open.xdmod.org for administrators who cannot upgrade immediately.

Attack Vector

The attack vector is network-based. An unauthenticated remote attacker sends a crafted HTTP or HTTPS request to a vulnerable Open XDMoD endpoint. The injected payload executes with the privileges of the web server process, commonly apache or www-data. From this foothold, attackers can pivot to internal HPC schedulers, exfiltrate research data, or stage further intrusions.

The vulnerability mechanism is described in the GitHub Security Advisory GHSA-29qm-7w4v-43fw. No public proof-of-concept exploit is available at the time of disclosure, and there is no evidence of exploitation in the wild.

Detection Methods for CVE-2026-45777

Indicators of Compromise

Unexpected child processes spawned by the web server user (apache, httpd, www-data) such as sh, bash, curl, wget, or python
HTTP request logs containing shell metacharacters (;, |, &&, backticks, $()) in query parameters or POST bodies targeting Open XDMoD endpoints
Outbound network connections from the Open XDMoD host to unfamiliar external IP addresses
Newly created files in web-writable directories or modifications to Open XDMoD configuration files

Detection Strategies

Review Apache or Nginx access logs for anomalous requests against Open XDMoD URI paths, particularly with encoded metacharacters
Deploy endpoint detection rules that identify the web server process forking command interpreters
Correlate web request activity with process execution telemetry to spot injection attempts that lead to shell execution
Audit Open XDMoD installations to confirm running version is 11.0.3 or later

Monitoring Recommendations

Enable verbose web server logging and forward logs to a centralized SIEM for correlation
Monitor process lineage on Open XDMoD hosts and alert on web server processes spawning shells or network utilities
Track outbound connections from HPC management nodes and flag traffic to non-allowlisted destinations
Establish a file integrity monitoring baseline for Open XDMoD installation directories and web roots

How to Mitigate CVE-2026-45777

Immediate Actions Required

Upgrade Open XDMoD to version 11.0.3 or later as documented in the v11.0.3-2 release notes
If immediate upgrade is not feasible, apply the official backport patch from the XDMod Security Patch GHSA-29qm-7w4v-43fw
Restrict network access to the Open XDMoD web interface using firewall rules or reverse proxy allowlists
Review web server and application logs for any historical signs of exploitation prior to patching

Patch Information

The Open XDMoD project released version 11.0.3 on May 12, 2026, addressing CVE-2026-45777. Administrators running versions 9.5.0 through 11.0.2 should upgrade immediately. A manual patch file is available for environments that cannot adopt the new release, referenced in GitHub Security Advisory GHSA-29qm-7w4v-43fw.

Workarounds

Apply the upstream patch manually to existing 9.5.0 through 11.0.2 deployments using the provided diff
Place Open XDMoD behind authenticated reverse proxy access until patching is complete
Restrict the web server account's shell access and remove unnecessary system utilities from its PATH
Enforce egress filtering on the Open XDMoD host to limit attacker post-exploitation options

bash

# Apply the official backport patch to Open XDMoD 9.5.0 - 11.0.2
cd /path/to/xdmod
curl -O https://open.xdmod.org/security_patches/GHSA-29qm-7w4v-43fw-9_5_0-11_0_2.patch
patch -p1 < GHSA-29qm-7w4v-43fw-9_5_0-11_0_2.patch
systemctl restart httpd