{"id":"UBUNTU-CVE-2026-27572","details":"Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime'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. Wasmtime 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. There are no known workarounds at this time. Embedders are encouraged to update to a patched version of Wasmtime.","modified":"2026-05-20T16:24:51.579075097Z","published":"2026-02-24T22:16:00Z","upstream":["CVE-2026-27572"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-27572"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-27572"},{"type":"REPORT","url":"https://rustsec.org/advisories/RUSTSEC-2026-0021.html"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h"},{"type":"REPORT","url":"https://docs.rs/http/1.4.0/http/header/#limitations"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4"}],"affected":[{"package":{"name":"rust-wasmtime","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10.0.1+dfsg-7","15.0.1+dfsg-4","16.0.0+dfsg-2","16.0.0+dfsg-3"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-cranelift-dev","binary_version":"0.103.0+16.0.0+dfsg-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27572.json"}},{"package":{"name":"rust-wasmtime","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["26.0.1+dfsg-3"],"ecosystem_specific":{"binaries":[{"binary_version":"0.113.1+26.0.1+dfsg-3","binary_name":"librust-cranelift-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27572.json"}},{"package":{"name":"rust-wasmtime","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["26.0.1+dfsg-3","26.0.1+dfsg-4","28.0.1+dfsg-3","29.0.1+dfsg-5","36.0.5+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-cranelift-dev","binary_version":"0.123.5+36.0.5+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27572.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}