PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In versions 4.0.0 through 5.8.0, 3.3.0 through 3.10.6, 2.2.0 through 2.4.6, 2.0.0 through 2.1.17, and all releases up to and including 1.30.5, the OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed .xls/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, OLERead::read() appends the same sector data repeatedly until the PHP process exhausts memory. This is reachable from Reader\Xls::canRead() and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file. This issue has been fixed in versions 5.8.1, 3.10.7, 2.4.7, 2.1.18 and 1.30.6.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation poc

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
PHPOffice PhpSpreadsheet affected
Version Status Constraints
>= 4.0.0, < 5.8.1 affected —
>= 3.3.0, < 3.10.7 affected —
>= 2.2.0, < 2.4.7 affected —
>= 2.0.0, < 2.1.18 affected —
< 1.30.6 affected —

No data.

No data.

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Project Subscriptions

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Phpspreadsheet Subscribe
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-xh5m-36r6-47m3 PHPSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/PHPOffice/PhpSpreadsheet/commit/85f2556b0bf5269061bf45932ecda8a128d81750 cve-icon
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.6 cve-icon
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.18 cve-icon
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.7 cve-icon
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.7 cve-icon
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.8.1 cve-icon
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3 cve-icon cve-icon
History

Tue, 28 Jul 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Phpoffice
Phpoffice phpspreadsheet
Vendors & Products Phpoffice
Phpoffice phpspreadsheet

Tue, 28 Jul 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 28 Jul 2026 18:00:00 +0000

Type Values Removed Values Added
Description PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In versions 4.0.0 through 5.8.0, 3.3.0 through 3.10.6, 2.2.0 through 2.4.6, 2.0.0 through 2.1.17, and all releases up to and including 1.30.5, the OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed .xls/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, OLERead::read() appends the same sector data repeatedly until the PHP process exhausts memory. This is reachable from Reader\Xls::canRead() and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file. This issue has been fixed in versions 5.8.1, 3.10.7, 2.4.7, 2.1.18 and 1.30.6.
Title PhpSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion
Weaknesses CWE-400
CWE-835
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-28T17:57:30.912Z

Reserved: 2026-07-07T18:20:06.126Z

Link: CVE-2026-59933

cve-icon Vulnrichment

Updated: 2026-07-28T17:57:27.458Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-28T19:30:16Z

Weaknesses