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Advisory record · RUSTSEC-2026-0264

`proc-macro-en` was removed from crates.io due to malicious code

No CVSS score

Published by OSV at 20 Aug 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
proc-macro-encrates.io>=0.0.0-0No fixed version yet
Identifiers
RUSTSEC-2026-0264
Published
20 Aug 2026
Updated
21 Aug 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The crates.io package proc-macro-en, which has no fixed version listed, was removed from crates.io for malicious code. It contained the same build script as proc-macro1 and was part of the same supply chain attack. The source gives few details on what the malicious build script does or how a user would be affected; it notes the crate was used in a malware campaign targeting users of arrayref.

Written 8 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

No source has published a CVSS score for this record yet.

  • CISA KEV Not listed.
  • EPSS No score.

Timeline

  1. 31 Oct 2026, 15:18 UTC First seen by agentprime
  2. 31 Oct 2026, 15:18 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.