CVE-2026-8257

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.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. Limited direct impact.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-11 02:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-23 20:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 1.9 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-11 02:16 UTC

Last modified

2026-07-23 20:10 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-617

Record status

Analyzed

Affected

• Webassembly Binaryen ≤ 117

Attack profile CVSS 4.0 · 1.9

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

None

Integrity

None

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-8257.md and follow it. Check whether this project is affected by CVE-2026-8257. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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