# CVE-2026-77649: internment Rust crate malicious dependency injection

Source: https://junglewise.ai/threats/cve-2026-77649-internment-rust-crate-malicious-dependency-injection  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-21. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77649 · Severity: critical · CVSS 9.8 · Published 2026-08-21

The internment Rust library version 0.8.7 was compromised and published with a malicious dependency that downloads and executes arbitrary code during project compilation. Any developer who compiled a project using this version would have their build system execute attacker-controlled code, potentially giving the attacker full control of their development machine, build pipeline, and access to sensitive credentials or source code.

Technologies: [internment (crates.io)](https://junglewise.ai/threats/technologies/internment). Vendors: [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is CVE-2026-77649 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77649 being exploited in the wild.

**How severe is CVE-2026-77649?** Critical severity, with a CVSS score of 9.8, published 21 August 2026.

**Which products and versions are affected?** internment (crates.io) 0.8.7.

**Is there a fix for CVE-2026-77649?** No fixed version is recorded yet. Check the vendor's advisory in the references below. 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 CVE-2026-77649 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-77649?** Check whether you run internment (crates.io) 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.

## Technical details

The internment crate 0.8.7 was republished with a rogue dependency (proc-macro1) containing a build script that downloads and executes a remote binary from 23.254.165.112:9089. The vulnerability is a supply-chain attack vector: when a developer runs `cargo build` on a project depending on internment 0.8.7, the build process executes the attacker-controlled payload automatically, with no user interaction required. The malicious code spawns a detached process on Unix systems (/tmp/rust-setup) and Windows systems via PowerShell, establishing command-and-control communication. The attack vector is network-based with no authentication required—any developer fetching this crate version from crates.io was affected. The crate was yanked and removed from crates.io within 90 minutes of publication; patches were applied by removing the malicious versions and restoring clean dependencies.

## Affected products

- Rust internment 0.8.7

## Timeline

- 2026-08-20: disclosed: Supply chain attack reported to Rust Security Response Team; malicious crate published
- 2026-08-20: other: Malicious version deleted from crates.io after 90 minutes online
- 2026-08-21: advisory: CVE-2026-77649 published

## References

- [https://blog.rust-lang.org/2026/08/20/supply-chain-attack-on-arrayref](https://blog.rust-lang.org/2026/08/20/supply-chain-attack-on-arrayref)
- [https://github.com/rustsec/advisory-db/issues/3161](https://github.com/rustsec/advisory-db/issues/3161)

## Related threats

- [arrayref crate malicious dependency code execution at build time](https://junglewise.ai/threats/cve-2026-77651-arrayref-crate-malicious-dependency-code-execution-at-build-time)
- [append-only-vec crate malicious build script supply chain attack](https://junglewise.ai/threats/cve-2026-77650-append-only-vec-crate-malicious-build-script-supply-chain-attack)
- [RUSTSEC-2026-0266 - `internment` 0.8.7 was removed from crates.io due to a malicious dependency](https://junglewise.ai/threats/rustsec-2026-0266-internment-0-8-7-was-removed-from-crates-io-due-to-a-8642dfec)
- [RUSTSEC-2021-0036 - Intern<T>: Data race allowed on T](https://junglewise.ai/threats/cve-2021-28037-data-race-in-internment)
- [RUSTSEC-2020-0017 - Use after free in ArcIntern::drop](https://junglewise.ai/threats/cve-2020-35874-use-after-free-in-internment)