CVE-2026-76241: stigmem-node RCE Vulnerability

CVE-2026-76241 Overview

CVE-2026-76241 affects stigmem-node version 0.9.0a1, where plugin signature enforcement can be disabled through a single configuration flag. The design lacks a second explicit acknowledgment step before disabling the security control. When operators propagate this setting into environments with writable plugin directories, unsigned plugin code can be loaded and executed by the runtime.

The issue is categorized under [CWE-494] Download of Code Without Integrity Check. It enables arbitrary code execution when less-trusted users can write to plugin paths. The upstream project fixed the flaw in 0.9.0a2, which now requires a second explicit acknowledgment to disable signature enforcement.

Critical Impact
Attackers with write access to plugin directories can execute arbitrary code within the stigmem-node process when signature enforcement is disabled.

Affected Products

stigmem-node version 0.9.0a1
Deployments carrying the disable-signature configuration flag into shared or multi-tenant hosts
Environments where plugin directories are writable by less-trusted users

Discovery Timeline

2026-08-19 - CVE-2026-76241 published to NVD
2026-08-19 - Last updated in NVD database

Technical Details for CVE-2026-76241

Vulnerability Analysis

The vulnerability stems from a permissive configuration design in stigmem-node. A single boolean flag controls whether plugin signatures are verified before load. Operators can toggle enforcement off without any secondary confirmation or runtime warning gate.

The risk materializes when that configuration is reused in an environment where plugin directories are writable by lower-privilege accounts. Under those conditions, an unprivileged local user can drop a malicious plugin into the load path. On the next plugin load cycle, stigmem-node executes the attacker-controlled code in the process context.

The root vulnerability class is [CWE-494] Download of Code Without Integrity Check. The exploitation requires local access and low privileges, but yields high impact on confidentiality, integrity, and availability of the affected node.

Root Cause

The signature enforcement setting is a single-step toggle. There is no defense-in-depth prompt, secondary acknowledgment, or environmental sanity check to prevent unsafe reuse of a permissive configuration across deployments.

Attack Vector

An attacker with write access to the plugin directory on a host running stigmem-node 0.9.0a1 with signature enforcement disabled can place an unsigned plugin. When the node loads plugins, the malicious code runs. Attack complexity is low, but exploitation depends on the presence of a specific misconfiguration and writable plugin paths.

No verified public exploit code is available. Refer to the GitHub Security Advisory and the VulnCheck Security Advisory for authoritative technical details.

Detection Methods for CVE-2026-76241

Indicators of Compromise

Presence of stigmem-node 0.9.0a1 binaries or packages on production hosts
Configuration files with signature enforcement flags set to disabled
Unsigned or unexpected plugin files appearing in the stigmem-node plugin directory
Plugin directories with write permissions granted to non-administrative users or groups

Detection Strategies

Inventory all hosts running stigmem-node and record the installed version and enforcement setting
Audit plugin directory contents against a known-good manifest of signed plugins
Flag process launches originating from plugins that were not present at last known-good state
Correlate configuration changes to the signature enforcement flag with subsequent plugin file writes

Monitoring Recommendations

Monitor filesystem events on stigmem-node plugin directories for file creation and modification by non-service accounts
Alert on configuration changes that disable plugin signature enforcement
Track child processes and outbound network activity from the stigmem-node process for behavioral anomalies

How to Mitigate CVE-2026-76241

Immediate Actions Required

Upgrade stigmem-node to version 0.9.0a2 or later, which requires a second explicit acknowledgment to disable signature enforcement
Re-enable plugin signature enforcement on all nodes and verify no unsigned plugins remain in load paths
Restrict write access on plugin directories to the service account and administrators only
Review configuration management templates so permissive enforcement flags are not propagated across environments

Patch Information

The project fixed the flaw in stigmem-node 0.9.0a2. The patched release enforces a second explicit acknowledgment before signature enforcement can be disabled, reducing the chance of accidental propagation. See the GitHub Security Advisory GHSA-w7pm-9g55-mxfm for release details.

Workarounds

Keep plugin signature enforcement enabled and reject configurations that disable it during code review
Apply strict filesystem ACLs so only trusted administrators can write to plugin directories
Segregate development and production configurations to prevent permissive flags from reaching production

bash

# Configuration example: restrict plugin directory permissions
chown -R stigmem:stigmem /var/lib/stigmem-node/plugins
chmod 750 /var/lib/stigmem-node/plugins
find /var/lib/stigmem-node/plugins -type f -exec chmod 640 {} \;

# Verify signature enforcement is enabled in the node configuration
grep -i 'signature_enforcement' /etc/stigmem-node/config.yaml