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CVE-2026-27572 Detail

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 6.9 MEDIUM
Vector:  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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://docs.rs/http/1.4.0/http/header/#limitations GitHub, Inc.
https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a GitHub, Inc.
https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6 GitHub, Inc.
https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6 GitHub, Inc.
https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4 GitHub, Inc.
https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4 GitHub, Inc.
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-770 Allocation of Resources Without Limits or Throttling GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-27572
NVD Published Date:
02/24/2026
NVD Last Modified:
02/24/2026
Source:
GitHub, Inc.