Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API
Summary
| CVE | CVE-2026-115389 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-22 19:17:46 UTC |
| Updated | 2026-10-22 19:17:46 UTC |
| Description | Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service. |
Risk And Classification
Primary CVSS: v4.0 1 LOW from [email protected]
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/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
Problem Types: CWE-770 | CWE-770 Allocation of Resources Without Limits or Throttling
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 1 | LOW | CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 1 | LOW | CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 2.3 | LOW | CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L |
| 3.1 | CNA | CVSS | 2.3 | LOW | CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L |
CVSS v4.0 Breakdown
Attack Vector
AdjacentAttack Complexity
HighAttack Requirements
PresentPrivileges Required
LowUser Interaction
PassiveConfidentiality
NoneIntegrity
NoneAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:A/AC:H/AT:P/PR:L/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
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
HighPrivileges Required
LowUser Interaction
RequiredScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
LowCVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Bytecodealliance | Wasmtime | affected 36.0.16 semver | Not specified |
| CNA | Bytecodealliance | Wasmtime | unaffected 36.0.16 semver | Not specified |
| CNA | Bytecodealliance | Wasmtime | affected 37.0.0 48.0.3 semver | Not specified |
| CNA | Bytecodealliance | Wasmtime | unaffected 48.0.3 semver | Not specified |
| CNA | Bytecodealliance | Wasmtime | affected 49.0.0 49.0.1 semver | Not specified |
| CNA | Bytecodealliance | Wasmtime | unaffected 49.0.1 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jqpg-j7w6-... | [email protected] | github.com | |
| www.vulncheck.com/advisories/wasmtime-before-36.0.16-37.0.0-before-48.0.3-and-4... | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: wilfreddenton (en)
There are currently no legacy QID mappings associated with this CVE.