How severe is CVE-2026-0821?

CVE-2026-0821 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-0821 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-0821?

CVE-2026-0821 affects Quickjs-ng Quickjs. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-0821?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-0821 have an EU (EUVD) identifier?

Yes. CVE-2026-0821 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1843.

When was CVE-2026-0821 published?

CVE-2026-0821 was published on 2026-01-10 and last updated on 2026-06-17.

CVE-2026-0821

CVE-2026-0821 is a high-severity vulnerability in Quickjs-ng Quickjs with a CVSS 3.x base score of 7.3. 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-119.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v2: 7.5
CVSS v4: 5.5
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-1843
Weakness: CWE-119
Affected product: Quickjs-ng Quickjs
Published: 2026-01-10
Last modified: 2026-06-17

Description

A vulnerability was determined in quickjs-ng quickjs up to 0.11.0. This vulnerability affects the function js_typed_array_constructor of the file quickjs.c. Executing a manipulation can lead to heap-based buffer overflow. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. This patch is called c5d80831e51e48a83eab16ea867be87f091783c5. A patch should be applied to remediate this issue.

Frequently asked questions

What is CVE-2026-0821?: A vulnerability was determined in quickjs-ng quickjs up to 0.11.0. This vulnerability affects the function js_typed_array_constructor of the file quickjs.c. Executing a manipulation can lead to heap-based buffer overflow. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. This patch is called c5d80831e51e48a83eab16ea867be87f091783c5. A patch should be applied to remediate this issue.
How severe is CVE-2026-0821?: CVE-2026-0821 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-0821 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-0821?: CVE-2026-0821 affects Quickjs-ng Quickjs. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-0821?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-0821 have an EU (EUVD) identifier?: Yes. CVE-2026-0821 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1843.
When was CVE-2026-0821 published?: CVE-2026-0821 was published on 2026-01-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:quickjs-ng:quickjs:*:*:*:*:*:*:*:*

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