{"answers":{"affected":"5 open source packages ship an affected version, including wasmtime.","exploited":"There is no known exploitation of CVE-2026-104855 in the wild and no public exploit code.","fix":"Upgrade wasmtime to a fixed version for your release line: 46.0.2 or 47.0.3.","what":"CVE-2026-104855 is a low-severity vulnerability in bytecodealliance wasmtime, published on 2 Oct 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-104855 and fix it if it is affected.\n\nWhat it is: CVE-2026-104855 is a low-severity vulnerability in bytecodealliance wasmtime, published on 2 Oct 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-104855 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- wasmtime (crates.io): affected from 46.0.0; fixed in 46.0.2, 47.0.3\n- wasmtime (crates.io): affected from 46.0.0; fixed in 46.0.2\n- wasmtime (crates.io): affected from 46.0.0; fixed in 46.0.2\n- wasmtime (crates.io): affected from 47.0.0; fixed in 47.0.3\n- wasmtime (crates.io): affected from 47.0.0; fixed in 47.0.3\n\nTask:\n1. 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.\n2. 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.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-104855/ (Markdown: https://insights.sbomify.com/CVE-2026-104855/index.md)","id":"CVE-2026-104855","markdown":"https://insights.sbomify.com/CVE-2026-104855/index.md","name":"CVE-2026-104855","record":{"aliases":["GHSA-2hw9-mc66-jc2q","MINI-8q69-px44-24m3","MINI-gw92-qq7c-qm3x","MINI-rh88-59v6-8775","RUSTSEC-2026-0223","UBUNTU-CVE-2026-104855"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"WebAssembly runtime","requires_auth":"high_privilege","summary":"Attackers can trigger memory corruption or crashes in Wasmtime by exploiting race conditions during preemption in bulk operations, requiring specific embedder configurations.","user_interaction":"required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":2,"severity":"low","source":"cna","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"Wasmtime is a runtime for WebAssembly. From 46.0.0 until 46.0.2 and 47.0.3, fuel and epoch preemption checks inside bulk operations including memory.copy, table.grow, and array.copy can expose invalid intermediate state when an embedder mutates a Store in Store::epoch_deadline_callback or continues using a Store after cancellation or a trap. A cancelled non-nullable table growth can leave null elements, linear-memory growth during memory.copy can invalidate retained raw pointers, and callback-triggered garbage collection during array.copy can invalidate GC pointers, resulting in a crash, invalid memory access, or GC heap corruption. Embeddings whose callbacks only access the host data in Store\u003cT\u003e, and embeddings that discard a Store after timeout or epoch deadline, are not affected. This issue is fixed in versions 46.0.2 and 47.0.3.","ecosystems":["crates.io"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Wasmtime: Preemption and traps during bulk operations enable breaking internal VM state","id":"CVE-2026-104855","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"crates.io","product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":5,"n_references":9,"next":{"headline":"Nx: OS command injection in the @nx/docker release pipeline","id":"CVE-2026-104859"},"packages":[{"ecosystem":"crates.io","fixed":["46.0.2","47.0.3"],"introduced":["46.0.0","47.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"RUSTSEC-2026-0223"},{"ecosystem":"crates.io","fixed":["46.0.2"],"introduced":["46.0.0"],"last_affected":[],"package":"wasmtime","purl":null,"source":"GHSA-2hw9-mc66-jc2q"},{"ecosystem":"crates.io","fixed":["46.0.2"],"introduced":["46.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"GHSA-2hw9-mc66-jc2q"},{"ecosystem":"crates.io","fixed":["47.0.3"],"introduced":["47.0.0"],"last_affected":[],"package":"wasmtime","purl":null,"source":"GHSA-2hw9-mc66-jc2q"},{"ecosystem":"crates.io","fixed":["47.0.3"],"introduced":["47.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"GHSA-2hw9-mc66-jc2q"}],"prev":{"headline":"Nx daemon and plugin worker sockets are accessible to other local users","id":"CVE-2026-104854"},"products":["wasmtime"],"published":"2026-10-02","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"open","licence":"CC0 1.0","name":"RustSec","prefix":"RUSTSEC"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-06","vendors":["bytecodealliance"]},"summary":"Attackers can trigger memory corruption or crashes in Wasmtime by exploiting race conditions during preemption in bulk operations, requiring specific embedder configurations.","url":"https://insights.sbomify.com/CVE-2026-104855/"}