Summary
electron-updater: Uncontrolled search path elements within AppImage built by app-builder-lib
AppImage targets built by app-builder-lib could use an empty path component when setting the LD_LIBRARY_PATH environment variable at runtime. This causes the current working directory to be added to the dynamic linker search path, which may allow an attacker to execute arbitrary code by placing a malicious shared library in the directory from which the AppImage is launched.
This vulnerability is the same class as CVE-2024-41817.
Details
The vulnerability existed in two independent code paths within app-builder-lib (toolset 1.0.0) and through upstream dependency app-builder-bin (toolset 0.0.0).
Path 1, Modern static runtime (AppRun generated by TypeScript)
The AppRun script generated by app-builder-lib contained this line:
export LD_LIBRARY_PATH="${APPDIR}/usr/lib:${LD_LIBRARY_PATH}"
When LD_LIBRARY_PATH is not set in the environment at launch time, this evaluates to:
/path/to/app.AppDir/usr/lib:
The trailing : is treated by the dynamic linker as an empty path component, which resolves to the current working directory. If an attacker can place a malicious shared library (e.g., libfoo.so) in the directory from which the AppImage is executed, that library will be loaded in place of the legitimate one, resulting in arbitrary code execution.
The same issue affected PATH, XDG_DATA_DIRS, and GSETTINGS_SCHEMA_DIR in the same script.
export LD_LIBRARY_PATH="${APPDIR}/usr/lib${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}"
Path 2, Legacy FUSE2 toolset (app-builder-bin)
AppImage targets built using the legacy FUSE2 toolset (toolsets.appimage = "0.0.0") delegated AppRun script generation to the app-builder-bin Go binary, which contained the same vulnerable template:
Affected Versions
This was fully resolved in [email protected] (commit 01b8ba979, PR #9829) when app-builder-bin was removed from the dependency tree entirely and all AppImage construction was migrated to the TypeScript implementation.
Workarounds
Set LD_LIBRARY_PATH to a non-empty value before launching the AppImage, so that the concatenation does not produce an empty path component. Alternatively, avoid running AppImage files from world-writable directories such as /tmp.
Impact
An attacker with the ability to write files to the directory from which a vulnerable AppImage is executed can cause arbitrary shared libraries to be loaded into the application process, resulting in arbitrary code execution with the privileges of the user running the AppImage.
CVE-2026-54672 has a CVSS score of 7.8 (High). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (26.15.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-54672? CVE-2026-54672 is a high-severity security vulnerability in app-builder-lib (npm), affecting versions < 26.15.0. It is fixed in 26.15.0.
- How severe is CVE-2026-54672? CVE-2026-54672 has a CVSS score of 7.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of app-builder-lib are affected by CVE-2026-54672? app-builder-lib (npm) versions < 26.15.0 is affected.
- Is there a fix for CVE-2026-54672? Yes. CVE-2026-54672 is fixed in 26.15.0. Upgrade to this version or later.
- Is CVE-2026-54672 exploitable, and should I be worried? Whether CVE-2026-54672 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-54672 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-54672? Upgrade
app-builder-libto 26.15.0 or later.