Use of Uninitialized Variable in wasm-micro-runtime - CVE-2026-54913
Published: August 5, 2026
Vulnerability identifier: #VU140982
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-54913
CWE-ID: CWE-457
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose host stack memory to the WebAssembly guest.
The vulnerability exists due to use of an uninitialized variable in load_init_expr in core/iwasm/interpreter/wasm_loader.c when parsing crafted WebAssembly global initialization expressions using ref.null with an invalid wide heap type. A remote attacker can supply a specially crafted WebAssembly module to disclose host stack memory to the WebAssembly guest.
Only the classic or fast interpreter loader is affected in builds with WASM_ENABLE_GC=0, and wider globals can increase the amount of leaked data.
Affected software
wasm-micro-runtime
How to mitigate CVE-2026-54913
Install security update from vendor's website.
wasm-micro-runtime - update to 2.4.5