qax-os Excelize up to 2.11.0 CFB Directory extractPart buffer size

Summaryinfo

A vulnerability classified as problematic has been found in qax-os Excelize up to 2.11.0. This impacts the function extractPart of the component CFB Directory Handler. The manipulation leads to buffer size. This vulnerability is uniquely identified as CVE-2026-107215. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in qax-os Excelize up to 2.11.0. This issue affects the function extractPart of the component CFB Directory Handler. The manipulation with an unknown input leads to a buffer size vulnerability. Using CWE to declare the problem leads to CWE-131. The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow. Impacted is availability. The summary by CVE is:

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.3.1 to 2.11.0, extractPart allocates a byte slice directly from an attacker-controlled CFB directory-entry size before validating the sector chain or size domain. extractPart trusts the CFB directory entry streamSize for EncryptionInfo and EncryptedPackage allocations before validating the stream. When a crafted OLE compound file declares a negative or extremely large EncryptionInfo or EncryptedPackage stream size, the declared size reaches make with a negative length or forces a multi-gigabyte allocation, allowing an attacker to panic or exhaust process memory. No fixed version is available as of this review.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-107215 since 10/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/07/2026).

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

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• qax-os

Name

• Excelize

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11.0

Website

• Product: https://github.com/qax-os/excelize/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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