Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

Informational severity, published 6 November 2026.

Which products and versions are affected?

build_dep (crates.io) SEMVER:introduced=0.0.0-0; Build Dep all versions (1 version: 0.0.0 or equivalent).

Is there a fix for This vulnerability?

No fixed version is recorded yet. Remove any dependency on build_dep from Cargo.toml files and audit build logs for evidence of the malicious telemetry transmission. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is This vulnerability attacked?

It is attacked over the network, in a software library.

Check whether you run build_dep (crates.io) or Build Dep at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

build_dep malicious code in Rust crate

Severity: info · Published 2026-11-06

A Rust build-time dependency package called build_dep was found to contain malicious code and removed from the crates.io repository. The package attempted to exfiltrate build environment data to an external server. Although it was available for approximately 20 months, there is no evidence it was used by any projects.

Vendors: crates.io.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: Informational severity, published 6 November 2026.
Which products and versions are affected?: build_dep (crates.io) SEMVER:introduced=0.0.0-0; Build Dep all versions (1 version: 0.0.0 or equivalent).
Is there a fix for This vulnerability?: No fixed version is recorded yet. Remove any dependency on build_dep from Cargo.toml files and audit build logs for evidence of the malicious telemetry transmission. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is This vulnerability attacked?: It is attacked over the network, in a software library.
Am I affected?: Check whether you run build_dep (crates.io) or Build Dep at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Remove any dependency on build_dep from Cargo.toml files and audit build logs for evidence of the malicious telemetry transmission.

Technical details

The build_dep Rust crate contained code that attempted to send telemetry data from the build environment to an attacker-controlled URL. This is a supply-chain attack delivered via a public package repository. Any project that added this crate as a build dependency would have had its build-time environment exposed, including environment variables, compiler flags, and system information.

Affected products

build_dep all versions (1 version: 0.0.0 or equivalent)

Timeline

2025-03-03: other: Malicious version published to crates.io
2026-11-06: disclosed: Vulnerability reported to RustSec
2026-11-10: advisory: Advisory issued; crate removed from crates.io

References

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