bellard QuickJS JS_ReadFunctionTag out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k0.00+

Summaryinfo

A vulnerability labeled as critical has been found in bellard QuickJS. Affected is the function JS_ReadFunctionTag. Such manipulation leads to out-of-bounds write. This vulnerability is documented as CVE-2026-88378. The attack can be executed remotely. There is not any exploit available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in bellard QuickJS (the affected version unknown) and classified as critical. Affected by this issue is the function JS_ReadFunctionTag. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

QuickJS commit 04be24600 contains a heap out-of-bounds write condition in JS_ReadFunctionTag().

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-88378 since 09/10/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

Applying the patch 04be24600 is able to eliminate this problem.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 04be24600

Timelineinfo

09/10/2026 CVE reserved
09/24/2026 +14 days Advisory disclosed
09/24/2026 +0 days VulDB entry created
09/24/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-88378 (🔒)
GCVE (CVE): GCVE-0-2026-88378
GCVE (VulDB): GCVE-100-409496

Entryinfo

Created: 09/24/2026 18:44
Changes: 09/24/2026 18:44 (54)
Complete: 🔍
Cache ID: 216::103

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