# RUSTSEC-2026-0242: Safe ErrorRegistry APIs can cause undefined behavior > Safe API misuse in dcrypt-api causes undefined behavior via use-after-free and type confusion, allowing potential code execution or crashes. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Not stated - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 9 Aug 2026 - **Also known as:** GHSA-7hc7-h3f2-r4j6 ## What is RUSTSEC-2026-0242? RUSTSEC-2026-0242 is an use after free vulnerability in dcrypt-api, published on 9 Aug 2026. ### Official description All published versions of `dcrypt-api` before 2.0.0 exposed safe `ErrorRegistry` operations that could trigger undefined behavior when the default `std` feature was enabled. Stored `Box` values were erased to raw pointers and later deallocated as `Box<()>`. The `get_error` operation also performed an unchecked cast to a caller-selected type. Finally, concurrent replacement or clearing could free a value while another thread cloned it. Ordinary safe Rust could therefore cause mismatched deallocation, type confusion, and use-after-free. Crates that re-exported this API are affected transitively. Version 2.0.0 replaces the raw pointers with owned `Box` values behind a mutex, performs checked downcasts, and uses a mutation generation so concurrent stores and clears win safely. There is no reliable workaround while calling the affected registry API. Upgrade to 2.0.0 or later and avoid process-global error state where possible. ## Which versions are affected by RUSTSEC-2026-0242? 1 open source package ship an affected version, including dcrypt-api. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `dcrypt-api` | crates.io | From 0.0.0-0 | 2.0.0 | ## How do I fix RUSTSEC-2026-0242? Upgrade dcrypt-api to 2.0.0 or later. ## Is RUSTSEC-2026-0242 being exploited? There is no known exploitation of RUSTSEC-2026-0242 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for RUSTSEC-2026-0242 and fix it if it is affected. What it is: RUSTSEC-2026-0242 is an use after free vulnerability in dcrypt-api, published on 9 Aug 2026. Exploitation: There is no known exploitation of RUSTSEC-2026-0242 in the wild and no public exploit code. Affected packages and fixed versions: - dcrypt-api (crates.io): affected from 0.0.0-0; fixed in 2.0.0 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/RUSTSEC-2026-0242/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0242/index.md) ``` ## Sources - OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0242 --- From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0242/ Summaries are generated and may contain mistakes; the official description above is the record.