CVE-2026-8257CWE-617

WebAssembly Binaryen BrOn wasm-ir-builder.cpp makeBrOn assertion

Medium · published May 11, 2026

CVSS v4.0
4.8
EPSS
0%
Percentile
8.1
In the wild
Unconfirmed
What it is

A vulnerability was detected in WebAssembly Binaryen up to 117. This issue affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Performing a manipulation results in reachable assertion. The attack needs to be approached locally. The exploit is now public and may be used. The patch is named 1251efbc1ea471c1311d2726b2bbe061ff2a291c. It is suggested to install a patch to address this issue.

The record
Technical detail
CVSS v4.0
4.8 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
EPSS
0.00189 · 8.1th percentile
Weakness
CWE-617 · Reachable Assertion
Published
2026-05-11T00:30Z
EPSS history
Timeline
  • 11 MAY 00:30Z
    WebAssembly Binaryen BrOn wasm-ir-builder.cpp makeBrOn assertion
    cvelistv5