CVE-2026-8257

Name: CVE-2026-8257
Creator: NVD / NIST
Published: 2026-05-11T02:16:27.09+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 1.9/10EPSS 0.16%

Last modified Jun 17, 2026

CVE-2026-8257 is a low-severity vulnerability rated 1.9/10 on the CVSS scale. 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. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.5/10

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

CVSS 4.0

1.9/10

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.16%

5.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-617

Affected Software

Vendor	Product	Versions
Webassembly	Binaryen	<= 117

References

https://github.com/HackC0der/CVE-Repos/blob/main/wasm-binaryen/Assertion_Failure_isRef_wasm_Type_getHeapType_commit_3ef8d19Exploit
https://github.com/WebAssembly/binaryen/Product
https://github.com/WebAssembly/binaryen/commit/1251efbc1ea471c1311d2726b2bbe061ff2a291cPatch
https://github.com/WebAssembly/binaryen/issues/8633Exploit, Issue Tracking, Third Party Advisory
https://github.com/WebAssembly/binaryen/pull/8635Mitigation, Patch
https://vuldb.com/submit/809552Third Party Advisory, VDB Entry
https://vuldb.com/vuln/362554Third Party Advisory, VDB Entry
https://vuldb.com/vuln/362554/ctiPermissions Required, VDB Entry

Timeline

Published: May 11, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-8257?

How severe is CVE-2026-8257?

CVE-2026-8257 has a CVSS score of 1.9/10 (LOW severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.

How do I fix CVE-2026-8257?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-8257?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST