GHSA-vq2f-vcc9-j8mv
GHSA-vq2f-vcc9-j8mv is a CWE-835 vulnerability in python-liquid. O3 Security confirms whether GHSA-vq2f-vcc9-j8mv is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Python Liquid: Infinite loop when parsing malformed `{% case %}` tags
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-vq2f-vcc9-j8mv.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
python-liquidReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Given a malformed {% case %} tag without associated {% when %} or {% else %} block, and no terminating {% endcase %} tag, Python Liquid hangs in an infinite loop at parse time. This allows malicious template authors to craft templates for a denial of service attack.
Patches
The issue is fixed in version 2.2.1 with the correction of the liquid.TokenStream.eof attribute. The kind and value of the special EOF token are now the same, so either can be tested against liquid.token.TOKEN_EOF.
Workarounds
Manually correct the definition of liquid.TokenStream.eof before parsing any templates.
import liquid
from liquid.token import TOKEN_EOF
liquid.stream.TokenStream.eof = liquid.Token(TOKEN_EOF, TOKEN_EOF, -1, "")
# ...
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | python-liquid | all versions | 2.2.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for python-liquid. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update python-liquid to 2.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vq2f-vcc9-j8mv is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-vq2f-vcc9-j8mv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-vq2f-vcc9-j8mv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-vq2f-vcc9-j8mv in your dependencies?
O3 detects GHSA-vq2f-vcc9-j8mv across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.