Which versions of fastapi-middleware-cors are malicious?

The following PyPI versions of fastapi-middleware-cors are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate fastapi-middleware-cors if I installed it?

fastapi-middleware-cors is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed fastapi-middleware-cors — how do I know if it already compromised me?

If fastapi-middleware-cors was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is fastapi-middleware-cors part of a known attack campaign?

Yes — fastapi-middleware-cors is associated with the 2026-03-fastapi-middleware-cors campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find fastapi-middleware-cors across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for fastapi-middleware-cors (version 1.0.0).

Malicious package

fastapi-middleware-corsPyPI

Advisory published Mar 13, 2026Updated Mar 14, 2026

fastapi-middleware-cors is a confirmed malicious PyPI package (MAL-2026-1422) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in fastapi-middleware-cors (PyPI)

MAL-2026-1422

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

pip uninstall fastapi-middleware-cors

What this malware does

Library disguised as FastAPI helper is executing obfuscated code during importing the module. The code is highly obfuscated; the code seems to contain an installation beacon reporting to a Telegram channel.

The package name appears as a dependency in a few Github repositories created long before publishing it, suggesting it might be an attempt to hijack the name that was previously wrongly generated by AI.

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-03-fastapi-middleware-cors

Reasons (based on the campaign):

typosquatting
obfuscation
exfiltration-generic

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

305178589615e2247b892b3e305e5fd69a0fc02092f0b115b6b384441f5ddd46

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for fastapi-middleware-cors (version 1.0.0).
If you installed it — respond
fastapi-middleware-cors is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If fastapi-middleware-cors was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. fastapi-middleware-cors on PyPI has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2026-03-fastapi-middleware-cors

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193) · reporter

Detect & block this

O3 blocks fastapi-middleware-cors-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database