VDB-410316 · CVE-2026-88389 · GCVE-0-2026-88389

Espruino Lexer src/jslex.c jslGetRawString null pointer dereference

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.3	$0-$5k	1.73+

Summaryinfo

A vulnerability was found in Espruino and classified as critical. Impacted is the function jslGetRawString of the file src/jslex.c of the component Lexer. The manipulation results in null pointer dereference. This vulnerability is identified as CVE-2026-88389. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Espruino (the affected version is unknown). It has been classified as critical. Affected is the function jslGetRawString of the file src/jslex.c of the component Lexer. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on integrity, and availability. CVE summarizes:

Espruino 2v29 (commit bffc6d0) contains a NULL pointer dereference vulnerability in jslGetRawString() in src/jslex.c. Crafted raw/binary string input can cause the lexer to pass a NULL iterator target to jsvLockAgain(). In RELEASE/NO_ASSERT builds, the missing assertion guard allows a write through the NULL pointer, resulting in memory corruption and application termination or denial of service.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-88389 since 09/10/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Espruino

Website

Product: https://github.com/espruino/Espruino/

CPE 2.3info

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CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.5
VulDB Temp Score: 6.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/10/2026 CVE reserved
09/25/2026 +15 days Advisory disclosed
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Not defined

CVE: CVE-2026-88389 (🔒)
GCVE (CVE): GCVE-0-2026-88389
GCVE (VulDB): GCVE-100-410316

Entryinfo

Created: 09/25/2026 16:46
Changes: 09/25/2026 16:46 (53)
Complete: 🔍
Cache ID: 216::103