{"answers":{"affected":"9 open source packages ship an affected version, including wasmtime. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-34941 in the wild and no public exploit code.","fix":"Upgrade wasmtime to a fixed version for your release line: 24.0.7, 36.0.7, 42.0.2 or 43.0.1.","what":"CVE-2026-34941 is a medium-severity memory corruption vulnerability in bytecodealliance wasmtime, published on 9 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-34941 and fix it if it is affected.\n\nWhat it is: CVE-2026-34941 is a medium-severity memory corruption vulnerability in bytecodealliance wasmtime, published on 9 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-34941 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- wasmtime (crates.io): affected all versions; fixed in 24.0.7\n- wasmtime (crates.io): affected all versions; fixed in 24.0.7\n- wasmtime (crates.io): affected from 0.0.0-0; fixed in 24.0.7, 36.0.7, 42.0.2, 43.0.1\n- wasmtime (crates.io): affected from 25.0.0; fixed in 36.0.7\n- wasmtime (crates.io): affected from 25.0.0; fixed in 36.0.7\n- wasmtime (crates.io): affected from 37.0.0; fixed in 42.0.2\n- wasmtime (crates.io): affected from 37.0.0; fixed in 42.0.2\n- wasmtime (crates.io): affected from 43.0.0; fixed in 43.0.1\n- wasmtime (crates.io): affected from 43.0.0; fixed in 43.0.1\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-2026-34941/ (Markdown: https://insights.sbomify.com/CVE-2026-34941/index.md)","id":"CVE-2026-34941","markdown":"https://insights.sbomify.com/CVE-2026-34941/index.md","name":"CVE-2026-34941","record":{"aliases":["DEBIAN-CVE-2026-34941","GHSA-hx6p-xpx3-jvvv","JLSEC-2026-1354","RUSTSEC-2026-0093","UBUNTU-CVE-2026-34941"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service","data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"WebAssembly runtime","requires_auth":"low_privilege","summary":"Attackers can cause a denial of service via segfault or potentially read host memory by exploiting a bounds check error in string transcoding.","user_interaction":"required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"wasmtime","vendor":"bytecodealliance"}],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds check. Specifically the number of code units were checked instead of the byte length, which is twice the size of the code units. This vulnerability can cause the host to read beyond the end of a WebAssembly's linear memory in an attempt to transcode nonexistent bytes. In Wasmtime's default configuration this will read unmapped memory on a guard page, terminating the process with a segfault. Wasmtime can be configured, however, without guard pages which would mean that host memory beyond the end of linear memory may be read and interpreted as UTF-16. A host segfault is a denial-of-service vulnerability in Wasmtime, and possibly being able to read beyond the end of linear memory is additionally a vulnerability. Note that reading beyond the end of linear memory requires nonstandard configuration of Wasmtime, specifically with guard pages disabled. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.","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 has a Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding","id":"CVE-2026-34941","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"crates.io","product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":9,"n_references":1,"next":{"headline":"Wasmtime panics when transcoding misaligned utf-16 strings","id":"CVE-2026-34942"},"packages":[{"ecosystem":"crates.io","fixed":["24.0.7"],"introduced":["0"],"last_affected":[],"package":"wasmtime","purl":null,"source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["24.0.7"],"introduced":["0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["24.0.7","36.0.7","42.0.2","43.0.1"],"introduced":["0.0.0-0","25.0.0","37.0.0","43.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"RUSTSEC-2026-0093"},{"ecosystem":"crates.io","fixed":["36.0.7"],"introduced":["25.0.0"],"last_affected":[],"package":"wasmtime","purl":null,"source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["36.0.7"],"introduced":["25.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["42.0.2"],"introduced":["37.0.0"],"last_affected":[],"package":"wasmtime","purl":null,"source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["42.0.2"],"introduced":["37.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["43.0.1"],"introduced":["43.0.0"],"last_affected":[],"package":"wasmtime","purl":null,"source":"GHSA-hx6p-xpx3-jvvv"},{"ecosystem":"crates.io","fixed":["43.0.1"],"introduced":["43.0.0"],"last_affected":[],"package":"wasmtime","purl":"pkg:cargo/wasmtime","source":"GHSA-hx6p-xpx3-jvvv"}],"prev":{"headline":"KubeAI: OS Command Injection via Model URL in Ollama Engine startup probe allows arbitrary command execution in model pods","id":"CVE-2026-34940"},"products":["wasmtime"],"published":"2026-04-09","related":[{"cvss_score":9,"headline":"Wasmtime miscompiled guest heap access enables sandbox escape on aarch64 Cranelift","id":"CVE-2026-34971","kev_date_added":null,"published":"2026-04-09"},{"cvss_score":9,"headline":"Wasmtime with Winch compiler backend on aarch64 may allow a sandbox-escaping memory access","id":"CVE-2026-34987","kev_date_added":null,"published":"2026-04-09"},{"cvss_score":8.6,"headline":"Wasmtime vulnerable to data leakage between instances in the pooling allocator","id":"CVE-2022-39393","kev_date_added":null,"published":"2022-11-10"},{"cvss_score":8.1,"headline":"Use after free in Wasmtime","id":"CVE-2022-24791","kev_date_added":null,"published":"2022-03-31"},{"cvss_score":7.5,"headline":"Wasmtime: WASI path_open(TRUNCATE) bypasses `FilePerms::WRITE` host restriction","id":"CVE-2026-47261","kev_date_added":null,"published":"2026-06-15"},{"cvss_score":6.9,"headline":"Wasmtime is vulnerable to panic when dropping a `[Typed]Func::call_async` future","id":"CVE-2026-27195","kev_date_added":null,"published":"2026-02-24"}],"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":"US public information, NVD API terms","name":"NVD"},{"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":"2026-04-10","vendors":["bytecodealliance"]},"summary":"Attackers can cause a denial of service via segfault or potentially read host memory by exploiting a bounds check error in string transcoding.","url":"https://insights.sbomify.com/CVE-2026-34941/"}