{"id":"GHSA-243v-98vx-264h","revision":"411b0cdc72224270b627433c516248ce","records":[{"revision":"411b0cdc72224270b627433c516248ce","observedAt":"2026-10-24T13:19:54.901+00:00","statement":{"source":"osv","id":"GHSA-243v-98vx-264h","aliases":["CVE-2026-27572","RUSTSEC-2026-0021"],"title":"Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance","description":"### Impact\n\nWasmtime's implementation of the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime's implementation in the `wasmtime-wasi-http` crate is backed by a data structure which panics when it reaches excessive capacity and this condition was not handled gracefully in Wasmtime. Panicking in a WASI implementation is a Denial of Service vector for embedders and is treated as a security vulnerability in Wasmtime.\n\n### Patches\n\nWasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 patch this vulnerability and return a trap to the guest instead of panicking.\n\n### Workarounds\n\nThere are no known workarounds at this time, embedders are encouraged to update to a patched version of Wasmtime.\n\n### Resources\n\n* [Limitations of `http::HeaderMap`](https://docs.rs/http/1.4.0/http/header/#limitations)","state":0,"publishedAt":"2026-02-24T21:08:06+00:00","modifiedAt":"2026-09-10T03:50:33.7288582+00:00","affected":[{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"24.0.6"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"25.0.0"},{"kind":"fixed","version":"36.0.6"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"37.0.0"},{"kind":"fixed","version":"40.0.4"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h","https://nvd.nist.gov/vuln/detail/CVE-2026-27572","https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a","https://docs.rs/http/1.4.0/http/header/#limitations","https://github.com/bytecodealliance/wasmtime","https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6","https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6","https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4","https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4","https://rustsec.org/advisories/RUSTSEC-2026-0021.html"],"sourceUrl":"https://github.com/advisories/GHSA-243v-98vx-264h","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-243v-98vx-264h","identifiers":["GHSA-243v-98vx-264h","CVE-2026-27572","RUSTSEC-2026-0021"]},"retained":false,"historicalAffected":[]}],"coverage":[]}