CVE-2025-14956 WebAssembly Binaryen wasm-binary.cpp readExport heap-based overflow

Medium 4.8 Published 19 Dec 2025 Updated 24 Feb 2026

A heap-based buffer overflow in WebAssembly Binaryen allows local attackers to execute arbitrary code or cause denial of service via crafted binaries.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2025-14956?

CVE-2025-14956 is a medium-severity memory corruption vulnerability in WebAssembly Binaryen, published on 19 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A vulnerability was determined in WebAssembly Binaryen up to 125. Affected by this issue is the function WasmBinaryReader::readExport of the file src/wasm/wasm-binary.cpp. This manipulation causes heap-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been publicly disclosed and may be utilized. Patch name: 4f52bff8c4075b5630422f902dd92a0af2c9f398. It is recommended to apply a patch to fix this issue.

Weakness: CWE-125, CWE-122, CWE-119

Which versions are affected by CVE-2025-14956?

It affects 1 product.

Products include Webassembly Binaryen.

How do I fix CVE-2025-14956?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-14956 being exploited?

There is no known exploitation of CVE-2025-14956 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2025-14956, GHSA-vjgx-vcpf-hm6w, JLSEC-2026-1092, UBUNTU-CVE-2025-14956.