Buffer overflow in Webassembly Binaryen

CVE-2025-14956

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (10.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-14956: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-14956?
CVE-2025-14956 is a medium-severity vulnerability in Webassembly Binaryen, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2025-12-19.
How severe is CVE-2025-14956?
Medium severity. CVSS v3 base score is 5.3 out of 10.