{
  "threat_severity" : "Moderate",
  "public_date" : "2026-04-09T18:29:30Z",
  "bugzilla" : {
    "description" : "wasmtime: Wasmtime: Denial of Service and potential information disclosure via incorrect UTF-16 string validation",
    "id" : "2456997",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2456997"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.3",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
    "status" : "draft"
  },
  "cwe" : "CWE-135",
  "details" : [ "Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds check. Specifically the number of code units were checked instead of the byte length, which is twice the size of the code units. This vulnerability can cause the host to read beyond the end of a WebAssembly's linear memory in an attempt to transcode nonexistent bytes. In Wasmtime's default configuration this will read unmapped memory on a guard page, terminating the process with a segfault. Wasmtime can be configured, however, without guard pages which would mean that host memory beyond the end of linear memory may be read and interpreted as UTF-16. A host segfault is a denial-of-service vulnerability in Wasmtime, and possibly being able to read beyond the end of linear memory is additionally a vulnerability. Note that reading beyond the end of linear memory requires nonstandard configuration of Wasmtime, specifically with guard pages disabled. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.", "A flaw was found in Wasmtime, a runtime for WebAssembly. When transcoding a UTF-16 string to the latin1+utf16 component-model encoding, Wasmtime incorrectly validates the byte length of the input string, checking the number of code units instead of the actual byte length. This vulnerability can lead to a Denial of Service (DoS) by causing the host process to terminate with a segmentation fault. In nonstandard configurations where guard pages are disabled, this flaw may also allow for information disclosure by reading beyond the end of WebAssembly's linear memory." ],
  "package_state" : [ {
    "product_name" : "Red Hat Connectivity Link 1",
    "fix_state" : "Affected",
    "package_name" : "redhat-user-workloads/rhcl-1-3-wasm-shim",
    "cpe" : "cpe:/a:redhat:connectivity_link:1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "virt-firmware-rs",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-34941\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-34941\nhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hx6p-xpx3-jvvv" ],
  "name" : "CVE-2026-34941",
  "mitigation" : {
    "value" : "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.",
    "lang" : "en:us"
  },
  "csaw" : false
}