CVE-2026-77651Known exploitationNetwork attack vector

Build-time code execution via malicious dependency

Published Aug 21, 2026 · Updated Aug 21, 2026

Malicious dependency injection in arrayref 0.3.10 allows remote attackers to execute code when Cargo compiles an affected project. The release's Cargo.toml adds proc-macro1 1.0.107, whose build.rs downloads and launches an architecture-specific binary. A Cargo build that resolves 0.3.10 is sufficient; the payload runs with the developer or CI runner's privileges on Unix or Windows hosts.

CVSS severity9.8
Critical
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Malicious dependency injection in arrayref 0.3.10 allows remote attackers to execute code when Cargo compiles an affected project. The release's Cargo.toml adds proc-macro1 1.0.107, whose build.rs downloads and launches an architecture-specific binary. A Cargo build that resolves 0.3.10 is sufficient; the payload runs with the developer or CI runner's privileges on Unix or Windows hosts.

The record

CVE
CVE-2026-77651
Published
Aug 21, 2026
Updated
Aug 21, 2026
Vendor
David Roundy
Product
arrayref
Classifications
CWE-506, T1195.001, T1105
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2026Exploitation reportedCrates.io arrayref supply-chain attack
  2. Aug 21, 2026CVE publishedPublication date reported by the CVE source.
  3. Aug 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.3.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

David Roundy · arrayrefversion=0.3.10

Published CVSS scores

9.8MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-506Embedded Malicious Code
T1195.001Compromise Software Dependencies
T1105Ingress Tool Transfer

Public exploit references

No public exploit references are available in this record.

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Reported exploitation

Technologies

Your stack

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Your stack

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