How severe is CVE-2026-8257?

CVE-2026-8257 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-8257 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-8257?

CVE-2026-8257 affects Webassembly Binaryen. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-8257?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-8257 have an EU (EUVD) identifier?

Yes. CVE-2026-8257 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29013.

When was CVE-2026-8257 published?

CVE-2026-8257 was published on 2026-05-11 and last updated on 2026-06-17.

CVE-2026-8257

CVE-2026-8257 is a low-severity vulnerability in Webassembly Binaryen with a CVSS 3.x base score of 3.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-617.

Key facts

Severity: Low (CVSS 3.x base score 3.3)
CVSS v2: 1.7
CVSS v4: 1.9
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29013
Weakness: CWE-617
Affected product: Webassembly Binaryen
Published: 2026-05-11
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-8257?: 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.
How severe is CVE-2026-8257?: CVE-2026-8257 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-8257 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-8257?: CVE-2026-8257 affects Webassembly Binaryen. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-8257?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-8257 have an EU (EUVD) identifier?: Yes. CVE-2026-8257 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29013.
When was CVE-2026-8257 published?: CVE-2026-8257 was published on 2026-05-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:webassembly:binaryen:*:*:*:*:*:*:*:*

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