CVE-2026-126408
Wasmtime 47.0.0 before 48.0.8 Denial of Service via TypedFunc Type-Check Panic
Wasmtime 47.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains an insufficient type-check in the TypedFunc embedder API for I31, Option<I31>, and Option<NoneRef> parameter or result types, reaching an unreachable!() path. A malicious guest module exporting a function that uses another anyref-hierarchy type can panic the host embedding, causing denial of service.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| wasmtime bytecodealliance wasmtime
cargo |
≥ 47.0.0; < 48.0.8 (affected, semver) 48.0.8 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
| wasmtime bytecodealliance wasmtime
cargo |
≥ 49.0.0; < 49.0.5 (affected, semver) 49.0.5 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
| wasmtime bytecodealliance wasmtime
cargo |
≥ 50.0.0; < 50.0.1 (affected, semver) 50.0.1 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 1.0 low |
CVSS:4.0/AV:A/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 1.8 low |
CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L | CNA: VulnCheck |
| 4.0 / 1.0 low |
CVSS:4.0/AV:A/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
| 3.1 / 1.8 low |
CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L | NVD: [email protected] |
Exploit evidence
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3982-jqvv-277m
exploit · ADP: CISA-ADP
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3982-jqvv-277mCNA: VulnCheck · vendor-advisory
- https://www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.8-denial-of-service-via-typedfunc-type-check-panicCNA: VulnCheck · third-party-advisory
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3982-jqvv-277mADP: CISA-ADP · exploit
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3982-jqvv-277m[email protected]
- https://www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.8-denial-of-service-via-typedfunc-type-check-panic[email protected]
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