PHPOffice PhpSpreadsheet up to 5.6.x XLSX File readRowAttributes allocation of resources

Summaryinfo

A vulnerability identified as problematic has been detected in PHPOffice PhpSpreadsheet up to 1.30.3/2.1.15/2.4.4/3.10.4/5.6.x. The affected element is the function ColumnAndRowAttributes::readRowAttributes of the component XLSX File Handler. Performing a manipulation results in allocation of resources. This vulnerability is known as CVE-2026-40902. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in PHPOffice PhpSpreadsheet up to 1.30.3/2.1.15/2.4.4/3.10.4/5.6.x. It has been classified as problematic. This affects the function ColumnAndRowAttributes::readRowAttributes of the component XLSX File Handler. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on availability. The summary by CVE is:

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0, the XLSX reader's ColumnAndRowAttributes::readRowAttributes() method reads row numbers from XML attributes without validating them against the spreadsheet maximum row limit (AddressRange::MAX_ROW = 1,048,576). An attacker can craft a minimal XLSX file (~1.6KB) containing a element that inflates cachedHighestRow to 999,999,999, causing any subsequent row iteration to attempt ~1 billion loop cycles and exhaust CPU resources. This vulnerability is fixed in 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-40902 since 04/15/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 1.30.4, 2.1.16, 2.4.5, 3.10.5 or 5.7.0 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• PHPOffice

Name

• PhpSpreadsheet

Version

• 1.30.0
• 1.30.1
• 1.30.2
• 1.30.3
• 2.1.0
• 2.1.1
• 2.1.2
• 2.1.3
• 2.1.4
• 2.1.5
• 2.1.6
• 2.1.7
• 2.1.8
• 2.1.9
• 2.1.10
• 2.1.11
• 2.1.12
• 2.1.13
• 2.1.14
• 2.1.15
• 2.4.0
• 2.4.1
• 2.4.2
• 2.4.3
• 2.4.4
• 3.10.0
• 3.10.1
• 3.10.2
• 3.10.3
• 3.10.4
• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.5
• 5.6

Website

• Product: https://github.com/PHPOffice/PhpSpreadsheet/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion