CVE-2026-126407
Wasmtime before 36.0.20 Denial of Service via Borrowed Resource Transfer
Wasmtime before 36.0.20, 37.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 allocates untracked host memory when a component receives a borrow of a resource it defines itself, bypassing the per-store handle limit. A malicious guest component can repeatedly transfer such borrowed resources to consume arbitrary host memory, 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 |
≥ 0; < 36.0.20 (affected, semver) 36.0.20 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
| wasmtime bytecodealliance wasmtime
cargo |
≥ 37.0.0; < 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 / 5.9 medium |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 4.8 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H | CNA: VulnCheck |
| 4.0 / 5.9 medium |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/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 / 4.8 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-6fr9-xmw9-5352CNA: VulnCheck · vendor-advisory
- https://www.vulncheck.com/advisories/wasmtime-before-36.0.20-denial-of-service-via-borrowed-resource-transferCNA: VulnCheck · third-party-advisory
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-6fr9-xmw9-5352[email protected]
- https://www.vulncheck.com/advisories/wasmtime-before-36.0.20-denial-of-service-via-borrowed-resource-transfer[email protected]
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