CVE-2026-88378: QuickJS · CVE-2026-88378 is a critical heap out-of-bounds write
Source CVE Database V5
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
Until a fix is available, consider limiting exposure of affected QuickJS instances to untrusted networks.
Description
CVE-2026-88378 is a critical heap out-of-bounds write vulnerability in QuickJS, specifically in the JS_ReadFunctionTag() function. It has a high CVSS score of 9.8, indicating severe impact on confidentiality, integrity, and availability. No affected versions or patch information are provided in the available data.