Which versions of bundlere are malicious?

The following RubyGems versions of bundlere are flagged malicious: 1.0.0, 1.0.43208. Treat any of these as compromised.

How do I remediate bundlere if I installed it?

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

If bundlere 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 bundlere part of a known attack campaign?

Yes — bundlere is associated with the RLMA-2026-07653 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 bundlere across my projects, lockfiles, and CI pipelines?

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

Malicious package

bundlereRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bundlere is a confirmed malicious RubyGems package (MAL-2026-16967) that executes malicious code on install (malicious versions 1.0.0, 1.0.43208). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bundlere (RubyGems)

MAL-2026-16967

Immediate action

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

gem uninstall bundlere

Malicious versions

2 flagged

1.0.01.0.43208

Indicators of compromise (SHA-256)

f2a969820907e22b4135bc5e4c565f9e09e916364d8afb11616f7b7ac77807fe

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bundlere (2 malicious versions).
If you installed it — respond
Remove bundlere 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 bundlere 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. bundlere on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.43208 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07653

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bundlere-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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