high CVSS 7.5 EPSS 0.34%

CVE-2026-45017·Python vulnerability

Python Liquid is a Python engine for the Liquid template language. Prior to 2.2.0, the built-in FileSystemLoader and CachingFileSystemLoader do not guard against reading files outside their search paths when given an absolute path to resolve. This allows malicious template authors to load and render arbitrary files via the {% include %} and {% render %} tags. Targeted files would need to contain valid Liquid markup and be readable by the application process. This vulnerability is fixed in 2.2.0.

Severity
high
Software
Python
Fixed in
2.2.0
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at 0.34% — higher than 25% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2026-45017 scores 7.5 on CVSS, so a successful attack would be serious — but at 0.34%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

Until: 2.2.0

Fixed in: 2.2.0

How to fix this CVE

Update Python Liquid to version 2.2.0 or later to patch the path traversal vulnerability in FileSystemLoader and CachingFileSystemLoader. If you use Python Liquid for template rendering, verify that your application only loads templates from designated directories and restrict absolute path resolution. After patching, test your template rendering pipeline to ensure no legitimate functionality is broken.

sudo dnf update python3-liquid

Defensia detects this vulnerability

How to check if you are affected

  1. Check Python Liquid version: python3 -c "import liquid; print(liquid.__version__)" or pip3 show liquid-template
  2. Identify applications using Python Liquid: grep -r "from liquid import" /opt /srv /home --include="*.py" 2>/dev/null or pip3 list | grep -i liquid
  3. Review template directories for suspicious include/render tags: grep -r "{% include" /path/to/templates --include="*.liquid" | grep -E "^/|\.\." to spot absolute or traversal paths
  4. Verify patch installation: python3 -m pip index versions liquid-template 2>/dev/null | head -20 and confirm installed version is >= 2.2.0

FAQ

What is CVE-2026-45017?

CVE-2026-45017 is a path traversal vulnerability in Python Liquid's template loaders that allows attackers to read and render arbitrary files from the server if an absolute file path is provided to the {% include %} or {% render %} tags, bypassing intended directory restrictions.

Is CVE-2026-45017 being actively exploited?

No, this vulnerability is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, prompt patching is still recommended due to its high severity.

What versions of Python Liquid are affected by CVE-2026-45017?

All versions of Python Liquid prior to 2.2.0 are affected. Version 2.2.0 and later contain the security fix.

How do I check if my server is vulnerable to CVE-2026-45017?

Run `pip3 show liquid-template | grep Version` to check the installed version. If the version is below 2.2.0, your server is vulnerable.

Does Defensia detect CVE-2026-45017?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Python Liquid is installed on a monitored server, CVE-2026-45017 will appear in your dashboard with remediation steps.

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References

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