How severe is CVE-2021-41127?

CVE-2021-41127 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-41127?

CVE-2021-41127 affects the following packages: rasa (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2021-41127?

Update rasa to 2.8.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41127 is resolved across your whole dependency graph.

How do I detect CVE-2021-41127 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rasa, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-41127 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2021-41127 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-41127 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-41127?

CVE-2021-41127 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-41127?

CVE-2021-41127 is classified as Path Traversal (CWE-22), CWE-23 (CWE-23). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-41127 published, and has it been updated?

CVE-2021-41127 was published on October 21, 2021 and was last updated on July 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

HIGH severity

CVE-2021-41127 — rasa

HIGHFix: RasaHQ/rasa@1b6b502

CVE-2021-41127 is a high-severity (CVSS 7.1) Path Traversal vulnerability in rasa. A fix is available for rasa — see the affected versions and patch details below.

Maliciously Crafted Model Archive Can Lead To Arbitrary File Write

Also known asGHSA-4365-fhm5-qcrxPYSEC-2021-381

Published

Oct 21, 2021

Updated

Jul 9, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-41127 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍rasa

Real-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

An Archive Extraction (Zip Slip) vulnerability in the functionality that allows a user to load a trained model archive in Rasa 2.8.9 and older allows an attacker arbitrary write capability within specific directories using a malicious crafted archive file.

Patches

The vulnerability is fixed in Rasa 2.8.10

Workarounds

Mitigating steps for vulnerable end users are to ensure that they do not upload untrusted model files, and restrict CLI or API endpoint access where a malicious actor could target a deployed Rasa instance.

For more information

If you have any questions or comments about this advisory:

Email the Rasa Security Team

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`rasa`	all versions	2.8.10`pip install --upgrade 'rasa==2.8.10'`

Affected Products

1 product · 1 configurations

Application

rasarasa

< 2.8.10

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rasa, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rasa to 2.8.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41127 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

### Impact An Archive Extraction (Zip Slip) vulnerability in the functionality that allows a user to load a trained model archive in Rasa 2.8.9 and older allows an attacker arbitrary write capability within specific directories using a malicious crafted archive file. ### Patches The vulnerability is fixed in Rasa 2.8.10 ### Workarounds Mitigating steps for vulnerable end users are to ensure that they do not upload untrusted model files, and restrict CLI or API endpoint access where a malicious actor could target a deployed Rasa instance. ### For more information If you have any questions or