Vulnerability-Lookup

rustsec-2026-0021

Vulnerability from osv_rustsec

Published

2026-02-24 12:00

Modified

2026-02-24 19:42

Summary

Panic adding excessive fields to a `wasi:http/types.fields` instance

Details

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h For more information see the GitHub-hosted security advisory.

JSON

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{
  "affected": [
    {
      "database_specific": {
        "categories": [],
        "cvss": "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",
        "informational": null
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime",
        "purl": "pkg:cargo/wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-0"
            },
            {
              "fixed": "24.0.6"
            },
            {
              "introduced": "25.0.0"
            },
            {
              "fixed": "36.0.6"
            },
            {
              "introduced": "37.0.0"
            },
            {
              "fixed": "40.0.4"
            },
            {
              "introduced": "41.0.0"
            },
            {
              "fixed": "41.0.4"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": []
    }
  ],
  "aliases": [
    "CVE-2026-27572",
    "GHSA-243v-98vx-264h"
  ],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "This is an entry in the RustSec database for the Wasmtime security advisory\nlocated at\nhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h\nFor more information see the GitHub-hosted security advisory.",
  "id": "RUSTSEC-2026-0021",
  "modified": "2026-02-24T19:42:18Z",
  "published": "2026-02-24T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/wasmtime"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0021.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h"
    }
  ],
  "related": [],
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Panic adding excessive fields to a `wasi:http/types.fields` instance"
}

GHSA-243V-98VX-264H

Vulnerability from github – Published: 2026-02-24 21:08 – Updated: 2026-02-24 21:08

Summary

Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance

Details

Impact

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.

Patches

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.

Workarounds

There are no known workarounds at this time, embedders are encouraged to update to a patched version of Wasmtime.

Resources

Limitations of http::HeaderMap

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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "24.0.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "25.0.0"
            },
            {
              "fixed": "36.0.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "37.0.0"
            },
            {
              "fixed": "40.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "wasmtime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "41.0.0"
            },
            {
              "fixed": "41.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-27572"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-24T21:08:06Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nWasmtime\u0027s implementation of the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime\u0027s 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.\n\n### Patches\n\nWasmtime 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.\n\n### Workarounds\n\nThere are no known workarounds at this time, embedders are encouraged to update to a patched version of Wasmtime.\n\n### Resources\n\n* [Limitations of `http::HeaderMap`](https://docs.rs/http/1.4.0/http/header/#limitations)",
  "id": "GHSA-243v-98vx-264h",
  "modified": "2026-02-24T21:08:06Z",
  "published": "2026-02-24T21:08:06Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a"
    },
    {
      "type": "WEB",
      "url": "https://docs.rs/http/1.4.0/http/header/#limitations"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/bytecodealliance/wasmtime"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance"
}

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

Vulnerability from cvelistv5 – Published: 2026-02-24 21:31 – Updated: 2026-02-24 21:31

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

GitHub_M

References

URL

Tags

	https://github.com/bytecodealliance/wasmtime/secu…	x_refsource_CONFIRM
	https://github.com/bytecodealliance/wasmtime/comm…	x_refsource_MISC
	https://docs.rs/http/1.4.0/http/header/#limitations	x_refsource_MISC
	https://github.com/bytecodealliance/wasmtime/rele…	x_refsource_MISC
	https://github.com/bytecodealliance/wasmtime/rele…	x_refsource_MISC
	https://github.com/bytecodealliance/wasmtime/rele…	x_refsource_MISC
	https://github.com/bytecodealliance/wasmtime/rele…	x_refsource_MISC

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

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "wasmtime",
          "vendor": "bytecodealliance",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 24.0.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 25.0.0, \u003c 36.0.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 37.0.0, \u003c 40.0.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 41.0.0, \u003c 41.0.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s implementation of the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime\u0027s 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": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-24T21:31:50.186Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h"
        },
        {
          "name": "https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a"
        },
        {
          "name": "https://docs.rs/http/1.4.0/http/header/#limitations",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://docs.rs/http/1.4.0/http/header/#limitations"
        },
        {
          "name": "https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6"
        },
        {
          "name": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6"
        },
        {
          "name": "https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4"
        },
        {
          "name": "https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4"
        }
      ],
      "source": {
        "advisory": "GHSA-243v-98vx-264h",
        "discovery": "UNKNOWN"
      },
      "title": "Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-27572",
    "datePublished": "2026-02-24T21:31:50.186Z",
    "dateReserved": "2026-02-20T17:40:28.448Z",
    "dateUpdated": "2026-02-24T21:31:50.186Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Action not permitted

rustsec-2026-0021

Vulnerability from osv_rustsec

GHSA-243V-98VX-264H

Impact

Patches

Workarounds

Resources

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

Tags

Sightings

Nomenclature