CVE-2026-27572 (GCVE-0-2026-27572)

Vulnerability from cvelistv5 – Published: 2026-02-24 21:31 – Updated: 2026-02-24 21:31
VLAI?
Title
Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance
Summary
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.
Severity ?
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
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Vendor Product Version
bytecodealliance wasmtime Affected: < 24.0.6
Affected: >= 25.0.0, < 36.0.6
Affected: >= 37.0.0, < 40.0.4
Affected: >= 41.0.0, < 41.0.4
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      "affected": [
        {
          "product": "wasmtime",
          "vendor": "bytecodealliance",
          "versions": [
            {
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              "version": "\u003c 24.0.6"
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            },
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              "status": "affected",
              "version": "\u003e= 37.0.0, \u003c 40.0.4"
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        }
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      "source": {
        "advisory": "GHSA-243v-98vx-264h",
        "discovery": "UNKNOWN"
      },
      "title": "Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance"
    }
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    "dateReserved": "2026-02-20T17:40:28.448Z",
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  }
}


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Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.