Which versions of bundleer are malicious?

The following RubyGems versions of bundleer are flagged malicious: 1.0.0, 1.0.40447. Treat any of these as compromised.

How do I remediate bundleer if I installed it?

Remove bundleer 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 bundleer — how do I know if it already compromised me?

If bundleer 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 bundleer part of a known attack campaign?

Yes — bundleer is associated with the RLMA-2026-07623 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 bundleer across my projects, lockfiles, and CI pipelines?

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

Malicious package

bundleerRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bundleer is a confirmed malicious RubyGems package (MAL-2026-16937) that executes malicious code on install (malicious versions 1.0.0, 1.0.40447). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bundleer (RubyGems)

MAL-2026-16937

Immediate action

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

gem uninstall bundleer

Malicious versions

2 flagged

1.0.01.0.40447

Indicators of compromise (SHA-256)

fe1575a0a21536e3c73783b97da95831428080ad45657ad59455f5cfa9465859

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bundleer (2 malicious versions).
If you installed it — respond
Remove bundleer 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 bundleer 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. bundleer on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.40447 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07623

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bundleer-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

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