PYSEC-2026-2496

Summary

glances/outdated.py uses pickle.load() to read a version-check cache file stored at a predictable, world-accessible path (~/.cache/glances/glances-version.db or $XDG_CACHE_HOME/glances/glances-version.db). No integrity check, signature verification, or format validation is performed before deserialization. An attacker with write access to that path — through any of several realistic local or container-level scenarios — can plant a malicious pickle file and achieve arbitrary code execution as the OS user running Glances the next time it starts with version checking enabled (the default).

Details

Affected file: glances/outdated.py, method Outdated._load_cache(), line 121

Direct URL (commit 04579778e733d705898a169e049dc84772c852da):

• https://github.com/nicolargo/glances/blob/04579778e733d705898a169e049dc84772c852da/glances/outdated.py#L121

# outdated.py  (_load_cache, line 119-127)
try:
    with open(self.cache_file, 'rb') as f:
        cached_data = pickle.load(f)          # ← no integrity check
except Exception as e:
    logger.debug(f"Cannot read version from cache file: {self.cache_file} ({e})")
    ...

self.cache_file is constructed from the XDG cache directory path at Outdated.__init__():

# outdated.py  (__init__)
self.cache_file = os.path.join(
    user_cache_dir('glances')[0],
    'glances-version.db'
)

On a default Linux installation this resolves to /home/john/.cache/glances/glances-version.db (or /root/.cache/glances/… when Glances runs as root).

Python's pickle module is an execution-capable serialisation format: any class that implements __reduce__ can embed an arbitrary callable and argument tuple that Python will invoke unconditionally at pickle.load() time. There is no safe subset of pickle; the only safe mitigation is to not use it for untrusted data.

The code was verified on x86_64 Linux, Python 3.13, Glances 4.5.5_dev1 (commit...