VulnerabilityPublished 26 Oct 2026

Cargo nextest: Arbitrary code execution when rerunning tests from a portable recording

Affects cargo-nextestSource GCVE Database

CVSS 7.8 High : upgrade to 0.9.150 soon.

Data as of 27 Oct 2026, 10:12 UTC

CVSS 3.1 base score

7.8High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 0.9.150

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

What to do

Upgrade cargo-nextest to 0.9.150.

Affected software

Product	Affected	Fixed in
crates.iocargo-nextest`pkg:cargo/cargo-nextest`Other threats	Affected >=0.9.125 <0.9.150	Fixed in 0.9.150

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Description

## Summary Nextest versions between 0.9.125 and 0.9.149 (inclusive) allow the `cargo nextest run --rerun` (or `-R`) command with a malicious [portable recording](https://nexte.st/docs/features/record-replay-rerun/portable-recordings/) to run arbitrary code during the build. The result is arbitrary code execution with the privileges of the user running `cargo nextest`. This vulnerability requires that the experimental [run recording](https://nexte.st/docs/features/record-replay-rerun/) functionality is enabled. An attacker can plausibly trick a victim into enabling this feature. ## Details Nextest's portable recordings contain [build scope arguments](https://nexte.st/docs/design/architecture/recording-runs/#build-scope-arguments). These arguments are deserialized verbatim from portable recordings, and are [not validated](https://github.com/nextest-rs/nextest/blob/70ba2393a05f29c54b72b4badb9635a86f162eb1/nextest-runner/src/record/format.rs#L421-L426). As a result, it is possible to construct an archive with a custom `--config` argument that causes Cargo to execute arbitrary code. Nextest 0.9.150 records the build scope as structured data, and passes each value to Cargo joined to its flag (for example, `--package=<value>`), so a recording can no longer add other Cargo options. ## Impact A malicious portable recording leads to arbitrary code execution as the user who runs `cargo nextest run --rerun`, during the build phase, before any test runs. - The injected configuration takes effect during `cargo build`, so the payload is run even on a warm build cache, and even when no tests are ultimately executed. Inspecting the recorded tests (with e.g. `cargo nextest replay`) before running them does not help, since the code has already run by the time the tests would start. - Arbitrary code execution happens as the invoking user, without a prompt or trust warning. The only signal is a `rerun: inheriting build scope…` line. On CI, this includes access to whatever secrets are accessible to the job, including repository tokens and deployment credentials. - A malicious payload can invoke the real compiler afterwards, so the build and tests complete normally. The recording is otherwise a valid, ordinary recording. - The full Cargo `--config` surface is exposed. This includes `build.rustc-wrapper`, `build.rustc`, `target.*.linker`, `target.*.runner`, `env.*`, and `patch.*` and `source.*.replace-with` (redirecting dependencies to an attacker-controlled repository or registry). - The delivery mechanism matches the feature's intended use, since portable recordings are designed to be shared across machines. For example, an attacker could pose as a user asking a maintainer for help triaging their flaky test report. Because `--rerun` also accepts process substitution, `cargo nextest run --rerun <(curl …)` would fetch the recording directly from a URL. Exploitation requires convincing the victim to run `cargo nextest run --rerun` against an attacker-supplied portable recording. The rerun feature is experimental and must be enabled, via e.g. `NEXTEST_EXPERIMENTAL_RECORD=1`. ## Remediations - Upgrade cargo-nextest to version 0.9.150 or above. - In your repositories, set the [minimum required version](https://nexte.st/docs/configuration/minimum-versions/) to 0.9.150. In `.config/nextest.toml`: ```toml nextest-version = "0.9.150" ``` This way, anyone who interacts with your repository will be notified to upgrade their version of nextest. - If you are using an affected version, do not enable the experimental run recording feature. ## Credit Reported by [inanna-malick](https://github.com/inanna-malick).

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