VDB-437000 · CVE-2026-128346 · GCVE-0-2026-128346

ExcelJS up to 4.4.0 WorkbookReader WorkbookReader.parse memory leak

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	0.21+

Summaryinfo

A vulnerability was found in ExcelJS up to 4.4.0 and classified as problematic. This vulnerability affects the function WorkbookReader.parse of the component WorkbookReader. Such manipulation leads to memory leak. This vulnerability is referenced as CVE-2026-128346. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in ExcelJS up to 4.4.0 and classified as problematic. Affected by this issue is the function WorkbookReader.parse of the component WorkbookReader. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. Impacted is availability. CVE summarizes:

ExcelJS through 4.4.0 contains a resource leak vulnerability in the streaming WorkbookReader.parse that leaves temporary files and open descriptors when sheet parsing fails or iteration stops early. Attackers can repeatedly upload malformed multi-sheet workbooks with worksheets placed before xl/sharedStrings.xml to fill the temporary directory and exhaust file descriptors.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-128346 since 11/13/2026. 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. The MITRE ATT&CK project declares the attack technique as T1499.

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

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

Productinfo

Name

ExcelJS

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

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: Memory leak
CWE: CWE-401 / 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

11/13/2026 Advisory disclosed
11/13/2026 +0 days CVE reserved
11/13/2026 +0 days VulDB entry created
11/13/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Not defined

CNA: VulnCheck
CVE: CVE-2026-128346 (🔒)

GCVE (CVE): GCVE-0-2026-128346
GCVE (VulDB): GCVE-100-437000

Entryinfo

Created: 11/13/2026 12:25
Changes: 11/13/2026 12:25 (74)
Complete: 🔍
Cache ID: 216::103