CVE-2026-8257 Details
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.
An assertion failure vulnerability has been identified in WebAssembly Binaryen versions prior to 117. The issue arises in the BrOn Parser component, specifically within the IRBuilder::makeBrOn function in the file wasm-ir-builder.cpp. The vulnerability is triggered by manipulating the parser with malformed WebAssembly input, leading to a reachable assertion failure. This issue must be approached locally, and the exploit is now public.
Users are advised to update to WebAssembly Binaryen version 117 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 11, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/HackC0der/CVE-Repos/blob/main/wasm-binaryen/Assertion_Failure_isRef_wasm_Type_getHeapType_commit_3ef8d19 | [email protected] | Exploit |
| https://github.com/WebAssembly/binaryen/ | [email protected] | Product |
| https://github.com/WebAssembly/binaryen/commit/1251efbc1ea471c1311d2726b2bbe061ff2a291c | [email protected] | Patch |
| https://github.com/WebAssembly/binaryen/issues/8633 | [email protected] | ExploitIssue TrackingThird Party Advisory |
| https://github.com/WebAssembly/binaryen/pull/8635 | [email protected] | MitigationPatch |
| https://vuldb.com/submit/809552 | [email protected] | Third Party AdvisoryVDB Entry |
| https://vuldb.com/vuln/362554 | [email protected] | Third Party AdvisoryVDB Entry |
| https://vuldb.com/vuln/362554/cti | [email protected] | Permissions RequiredVDB Entry |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-617 | Reachable Assertion | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| webassembly binaryen | <= 117 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 21, 2026 | Initial Analysis | [email protected] |
| May 11, 2026 | New CVE Received | [email protected] |