UBUNTU-CVE-2026-47261

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Source
https://ubuntu.com/security/CVE-2026-47261
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-47261.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-47261
Upstream
Published
2026-06-15T21:17:00Z
Modified
2026-06-24T11:01:44.558851948Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Wasmtime is a runtime for WebAssembly. In versions prior to 24.0.9, 36.0.10, and 44.0.2, when a filesystem preopen is given DirPerms::all() and FilePerms::READ without FilePerms::WRITE, this access control mechanism can be bypassed via the wasip2 descriptor.open-at or wasip1 pathopen interfaces by opening a file with only the OpenFlags::TRUNCATE oflag. The root cause is that the clause handling OpenFlags::TRUNCATE in crates/wasi/src/filesystem.rs (Dir::openat, lines 967–969) did not set openmode |= OpenMode::WRITE;, which is later used for the access control check against FilePerms to determine whether opening the file is permitted; the single-line fix adds that missing assignment, after which the affected calls correctly fail with error-code.not-permitted and ERRNOPERM respectively. Only wasmtime-wasi embeddings that combine DirPerms::MUTATE with FilePerms::READ are affected by this bug. In particular, the Wasmtime project's wasmtime-cli's use of wasmtime-wasi is not affected, because it always sets FilePerms::all() for all preopens. This issue has been fixed in versions 24.0.9, 36.0.10 and44.0.2.

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-2026-47261.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-2026-47261.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-2026-47261.json"