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Quickjs - Security Vulnerability (CVE-2026-0821)

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.

CVE-2026-0821

MEDIUM CVSS 6.9 Published 2026-01-10 Updated 2026-02-23
AI Risk Elevated (69/100) Active Exploit: No strong signal Published Exploit: Public exploit references found Priority: P3 Priority
Severity Band MEDIUM
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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
Affected Components 1
Reference Links 8
AI Risk Engine Elevated (69/100)
Exploitability Medium
Active Exploitation No strong signal
Published Exploit Status Public exploit references found

Threat Timeline

  1. 2026-01-10 CVE published and first recorded in the threat feed.
  2. 2026-02-23 Record updated with latest vulnerability metadata.
  3. 2026-04-09 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 153 days ago

AI enriched 153 days ago (2026-04-09 08:18 UTC)

Technical Summary

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.

Potential Impact

Severity is MEDIUM (CVSS 6.9). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Medium based on published exploit references.

Primary risk drivers: published exploit references

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Quickjs PLUGIN · quickjs Affected: >= 0.1, <= 0.1 Fixed version not specified

References

What to do about this

Patch on your next cycle Worth fixing, but not ahead of other work.

Fix it

Update Quickjs to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

No Hack Halt control meaningfully contains this one — updating is the remedy. We would rather say so than sell you something that will not help.

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Not sure if you are affected?

Scan your site to see whether it runs Quickjs, and at which version.

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Am I affected by this vulnerability?

You are affected if your site runs Quickjs.

How do I fix it?

Update Quickjs to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do.