Vulnerability in WebAssembly Binaryen (CVE-2026-8257)
Summary
Vulnerability in WebAssembly Binaryen (CVE-2026-8257). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-8257 has been found in WebAssembly Binaryen.
Risk of unauthorized operations or information disclosure. CVSS score: 3.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "WebAssembly Binaryen CVE-2026-8257" on the vendor's site.
CVE-2026-8257 (WebAssembly Binaryen) — CWE-617 / CVSS v3 3.3
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-617) exists in WebAssembly Binaryen.
Check the vendor advisory for the affected versions of WebAssembly Binaryen.
Severity: Low (CVSS 3.3/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで WebAssembly Binaryen を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-8257 binaryen
- Ubuntu UBUNTU-CVE-2026-8257 binaryen
References
- advisory cna@vuldb.com
- advisory cna@vuldb.com
- exploit cna@vuldb.com
- exploit cna@vuldb.com
- patch cna@vuldb.com
- patch cna@vuldb.com
- web cna@vuldb.com
- web cna@vuldb.com
- web nvd.nist.gov
- web github.com
- web github.com