CVE-2026-54786

Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fd_renumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of descriptors used by the host. This behavior means that while fd_renumber works correctly from a guest's perspective it ends up leaking resources in the host that aren't cleaned up until the corresponding Store is destroyed. In a loop, guests can use fd_renumber to cause hosts to exhaust both resources and file descriptors. This bug only affects the native implementation of WASIp1, meaning that only runtimes which load core wasm modules and expose fd_renumber are affected. Runtimes are additionally only affected if they expose the ability to acquire a file descriptor, such as opening a file. For runtimes that deny access to files they are unaffected. This issue has been fixed in versions 24.0.10, 36.0.11, 44.0.3, and 45.0.2.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*
cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*
cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*
cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*

History

02 Jul 2026, 19:27

Type Values Removed Values Added
References () https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3p27-qvp9-27qf - () https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3p27-qvp9-27qf - Vendor Advisory
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.0
CPE cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*
First Time Bytecodealliance
Bytecodealliance wasmtime

01 Jul 2026, 21:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-07-01 21:17

Updated : 2026-07-02 19:27


NVD link : CVE-2026-54786

Mitre link : CVE-2026-54786

CVE.ORG link : CVE-2026-54786


JSON object : View

Products Affected

bytecodealliance

  • wasmtime
CWE
CWE-400

Uncontrolled Resource Consumption

CWE-772

Missing Release of Resource after Effective Lifetime