CVE-2026-8257

WebAssembly Binaryen BrOn wasm-ir-builder.cpp makeBrOn assertion

MEDIUM
5.5
CVSS Score
Published: May 11, 2026 at 12:30 AM UTC
Updated: July 23, 2026 at 09:11 PM UTC
1 product affected across 1 vendorBinaryen

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (8)

VDB EntryTechnical DescriptionThird Party Advisory
Source: cverecord
https://vuldb.com/vuln/362554
SignaturePermissions RequiredVDB Entry
Source: cverecord
https://vuldb.com/vuln/362554/cti
Third Party AdvisoryVDB Entry
Source: cverecord
https://vuldb.com/submit/809552
Issue TrackingExploitThird Party Advisory
Source: cverecord
https://github.com/WebAssembly/binaryen/issues/8633
Issue TrackingPatchMitigation
Source: cverecord
https://github.com/WebAssembly/binaryen/pull/8635

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-617

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