CVE-2020-18378: Webassembly Binaryen

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

A NULL pointer dereference was discovered in SExpressionWasmBuilder::makeBlock in wasm/wasm-s-parser.c in Binaryen 1.38.26. A crafted wasm input can cause a segmentation fault, leading to denial-of-service, as demonstrated by wasm-as.

Affected products

• Webassembly Binaryen: version 1.38.26 only

Published 2023-08-22. Last modified 2026-06-17.