Which versions of baundler are malicious?

The following RubyGems versions of baundler are flagged malicious: 1.0.0, 1.0.89456. Treat any of these as compromised.

How do I remediate baundler if I installed it?

Remove baundler from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed baundler — how do I know if it already compromised me?

If baundler 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 baundler part of a known attack campaign?

Yes — baundler is associated with the RLMA-2026-07215 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 baundler across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for baundler (2 malicious versions).

Malicious package

baundlerRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

baundler is a confirmed malicious RubyGems package (MAL-2026-16568) that executes malicious code on install (malicious versions 1.0.0, 1.0.89456). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in baundler (RubyGems)

MAL-2026-16568

Immediate action

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

gem uninstall baundler

Malicious versions

2 flagged

1.0.01.0.89456

Indicators of compromise (SHA-256)

ad2dccc0a7b423650c068dbf894a4b4c69260484638867a75908c6c4c5fe4d21

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for baundler (2 malicious versions).
If you installed it — respond
Remove baundler from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If baundler 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. baundler on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.89456 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07215

Credits

ReversingLabs · finder

Detect & block this

O3 blocks baundler-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Malware detection Runtime egress monitoring

Explore

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