{"id":"CVE-2026-119135","state":"PUBLISHED","title":"Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Panic via StreamReader Type Mismatch","description":"Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 panics when the host reads a component model stream as a different Rust item type than it was created with, because the host-to-host read path asserts matching TypeIds instead of returning an error. Guest code can return a host-created StreamReader<U> that the embedder reads as StreamReader<T>, where both types map to the same component model type, crashing the embedding process.","publishedAt":"2026-10-29T15:58:15.914Z","updatedAt":"2026-10-29T15:58:15.914Z","severity":{"score":5.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["bytecodealliance wasmtime"],"affected":[{"vendor":"bytecodealliance","product":"wasmtime","packageURL":"pkg:cargo/wasmtime","defaultStatus":"unaffected","versions":[{"version":"46.0.0","status":"affected","lessThan":"48.0.6","versionType":"semver"},{"version":"48.0.6","status":"unaffected","versionType":"semver"},{"version":"49.0.0","status":"affected","lessThan":"49.0.3","versionType":"semver"},{"version":"49.0.3","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-63h4-6cx9-pjfj","https://www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.6-and-49.0.0-before-49.0.3-panic-via-streamreader-type-mismatch"],"weaknesses":["CWE-617"],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/119xxx/CVE-2026-119135.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-119135","state":"PUBLISHED","datePublished":"2026-10-29T15:58:15.914Z","dateUpdated":"2026-10-29T15:58:15.914Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-29T14:26:15.522Z"},"containers":{"cna":{"title":"Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Panic via StreamReader Type Mismatch","descriptions":[{"lang":"en","value":"Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 panics when the host reads a component model stream as a different Rust item type than it was created with, because the host-to-host read path asserts matching TypeIds instead of returning an error. Guest code can return a host-created StreamReader<U> that the embedder reads as StreamReader<T>, where both types map to the same component model type, crashing the embedding process."}],"affected":[{"vendor":"bytecodealliance","product":"wasmtime","packageURL":"pkg:cargo/wasmtime","defaultStatus":"unaffected","versions":[{"version":"46.0.0","status":"affected","lessThan":"48.0.6","versionType":"semver"},{"version":"48.0.6","status":"unaffected","versionType":"semver"},{"version":"49.0.0","status":"affected","lessThan":"49.0.3","versionType":"semver"},{"version":"49.0.3","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-63h4-6cx9-pjfj","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-63h4-6cx9-pjfj)"},{"url":"https://www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.6-and-49.0.0-before-49.0.3-panic-via-streamreader-type-mismatch","name":"VulnCheck Advisory: Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Panic via StreamReader Type Mismatch","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":4.8,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-617","lang":"en","description":"Reachable Assertion","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-29T15:58:15.914Z"},"datePublic":"2026-10-14T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*","versionStartIncluding":"46.0.0","versionEndExcluding":"48.0.6"},{"vulnerable":true,"criteria":"cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*","versionStartIncluding":"49.0.0","versionEndExcluding":"49.0.3"}]}]}],"credits":[{"lang":"en","value":"tschneidereit","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}}