CVEvulnerability
CVE-2026-27572
6.9 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-02-24
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 6.9 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:H/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 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-770
Description
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.
Affected configurations
• bytecodealliance wasmtime (< 24.0.6)
• bytecodealliance wasmtime (>= 25.0.0 < 36.0.6)
• bytecodealliance wasmtime (>= 37.0.0 < 40.0.4)
• bytecodealliance wasmtime (>= 41.0.0 < 41.0.4)
Related
Weakness · CWE (1)
- CWE-770 Allocation of Resources Without Limits or Throttling weakness
References
- https://docs.rs/http/1.4.0/http/header/#limitations Not Applicable
- https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a Patch
- https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6 Product, Release Notes
- https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6 Product, Release Notes
- https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4 Product, Release Notes
- https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4 Product, Release Notes
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h Third Party Advisory