Heap Out-of-Bounds Write Vulnerability in QuickJS by Bellard
CVE-2026-88378

9.8CRITICAL

Key Information:

Vendor

Bellard

Status
QuickJS
Vendor
CVE Published:
24 September 2026

What is CVE-2026-88378?

A vulnerability exists in QuickJS resulting from a heap out-of-bounds write condition within the JS_ReadFunctionTag() function. This flaw could potentially allow a malicious actor to execute arbitrary code through crafted JavaScript inputs, leading to significant security risks. Users of affected QuickJS versions are strongly advised to apply available patches to mitigate the risk associated with this vulnerability.

References

https://github.com/bellard/quickjs/issues/549
https://github.com/bellard/quickjs/pull/553
https://github.com/bellard/quickjs/pull/553/changes/42526...

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.