WebAssembly Binaryen up to 117 BrOn Parser wasm-ir-builder.cpp IRBuilder::makeBrOn assertion

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.9$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in WebAssembly Binaryen up to 117. Impacted is the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. Executing a manipulation can lead to assertion. The identification of this vulnerability is CVE-2026-8257. The attack can only be executed locally. Furthermore, there is an exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability was found in WebAssembly Binaryen up to 117. It has been declared as problematic. This vulnerability affects the function IRBuilder::makeBrOn of the file src/wasm/wasm-ir-builder.cpp of the component BrOn Parser. The manipulation with an unknown input leads to a assertion vulnerability. The CWE definition for the vulnerability is CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. As an impact it is known to affect availability.

The advisory is available at github.com. This vulnerability was named CVE-2026-8257. The exploitation appears to be easy. Local access is required to approach this attack. Technical details and also a public exploit are known.

It is possible to download the exploit at github.com. It is declared as proof-of-concept.

Applying the patch 1251efbc1ea471c1311d2726b2bbe061ff2a291c is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at CNNVD (CNNVD-202605-2396). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 3.9

VulDB Base Score: 3.3
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CNA Base Score: 3.3
CNA Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Assertion
CWE: CWE-617
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 1251efbc1ea471c1311d2726b2bbe061ff2a291c

Timelineinfo

05/10/2026 Advisory disclosed
05/10/2026 +0 days VulDB entry created
05/22/2026 +12 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 8633
Status: Confirmed
Confirmation: 🔒

CVE: CVE-2026-8257 (🔒)
GCVE (CVE): GCVE-0-2026-8257
GCVE (VulDB): GCVE-100-362554
CNNVD: CNNVD-202605-2396 - Binaryen 安全漏洞

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 05/10/2026 17:02
Updated: 05/22/2026 08:14
Changes: 05/10/2026 17:02 (61), 05/13/2026 08:06 (6), 05/22/2026 08:14 (41)
Complete: 🔍
Submitter: pwn3rd
Cache ID: 216::103

Submitinfo

Accepted

  • Submit #809552: WebAssembly Community Binaryen main branch commit 3ef8d19 (v117 development version, vulnerable version before fix commit 1251efb) Fixed version: commit 1251ef Assertion Failure, Denial of Service (Local DoS) (by pwn3rd)

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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