UBUNTU-CVE-2026-34942

Source
https://ubuntu.com/security/CVE-2026-34942
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34942.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-34942
Upstream
Published
2026-04-09T19:16:00Z
Modified
2026-05-20T16:12:55.181826710Z
Severity
  • 5.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L CVSS Calculator
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of transcoding strings into the Component Model's utf16 or latin1+utf16 encodings improperly verified the alignment of reallocated strings. This meant that unaligned pointers could be passed to the host for transcoding which would trigger a host panic. This panic is possible to trigger from malicious guests which transfer very specific strings across components with specific addresses. Host panics are considered a DoS vector in Wasmtime as the panic conditions are controlled by the guest in this situation. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.

References

Affected packages

Ubuntu:24.04:LTS / rust-wasmtime

Package

Name
rust-wasmtime
Purl
pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

10.*
10.0.1+dfsg-7
15.*
15.0.1+dfsg-4
16.*
16.0.0+dfsg-2
16.0.0+dfsg-3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-cranelift-dev",
            "binary_version": "0.103.0+16.0.0+dfsg-3"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34942.json"

Ubuntu:25.10 / rust-wasmtime

Package

Name
rust-wasmtime
Purl
pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=questing

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

26.*
26.0.1+dfsg-3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-cranelift-dev",
            "binary_version": "0.113.1+26.0.1+dfsg-3"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34942.json"

Ubuntu:26.04:LTS / rust-wasmtime

Package

Name
rust-wasmtime
Purl
pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

26.*
26.0.1+dfsg-3
26.0.1+dfsg-4
28.*
28.0.1+dfsg-3
29.*
29.0.1+dfsg-5
36.*
36.0.5+dfsg-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "librust-cranelift-dev",
            "binary_version": "0.123.5+36.0.5+dfsg-1"
        }
    ]
}

Database specific

source
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34942.json"