CVE-2026-8257

medium

Description

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.

References

https://vuldb.com/vuln/362554

https://vuldb.com/submit/809552

https://github.com/HackC0der/CVE-Repos/blob/main/wasm-binaryen/Assertion_Failure_isRef_wasm_Type_getHeapType_commit_3ef8d19

https://vuldb.com/vuln/362554/cti

https://github.com/WebAssembly/binaryen/pull/8635

https://github.com/WebAssembly/binaryen/issues/8633

https://github.com/WebAssembly/binaryen/commit/1251efbc1ea471c1311d2726b2bbe061ff2a291c

https://github.com/WebAssembly/binaryen/

Details

Source: Mitre, NVD

Published: 2026-05-11

Updated: 2026-05-21

Risk Information

CVSS v2

Base Score: 1.7

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:P

Severity: Low

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

CVSS v4

Base Score: 4.8

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

Severity: Medium

EPSS

EPSS: 0.00013