← Vulnerability feed

Vulnerability record · CVE-2026-59933 · published 28 July 2026

CVE-2026-59933: Uncontrolled resource consumption vulnerability

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.

7.5 CVSS 3.1 High EPSS 0.70% · top 48.8% CWE-400 · Uncontrolled resource consumptionCWE-835 · CWE-835 Deferred
7.5CVSS 3.1 base score
0.70%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
8References
30 Jul 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

LinkTags
https://github.com/PHPOffice/PhpSpreadsheet/commit/85f2556b0bf5269061bf45932ecda8a128d81750
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.6
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.18
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.7
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.7
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.8.1
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3

Track CVE-2026-59933 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.5CVE-2026-28318SolarWinds Serv-U unauthenticated POST request denial of serviceSolarWinds Serv-U crashes when it receives a specially crafted POST request using Content-Encoding: deflate, and the crash occurs without authenticat…KEVEPSS 1.9%analysed7.5CVE-2026-45498Microsoft Defender antimalware platform uncontrolled resource consumption DoSCVE-2026-45498 is a denial of service flaw in the Microsoft Defender antimalware platform, classified as uncontrolled resource consumption (CWE-400).…KEVEPSS 1.3%analysed7.5CVE-2023-44487HTTP/2 Rapid Reset stream cancellation denial of serviceThe HTTP/2 protocol permits a client to cancel many streams quickly, and the server's handling of those resets consumes disproportionate resources. T…KEVEPSS 100%analysed7.5CVE-2023-38180Microsoft .NET and Visual Studio uncontrolled resource consumption DoSCVE-2023-38180 is a denial-of-service flaw in Microsoft .NET, ASP.NET Core and Visual Studio 2022, classified as uncontrolled resource consumption (C…KEVEPSS 14%analysed5.9CVE-2004-1464Cisco IOS Telnet VTY resource exhaustion denial of serviceCisco IOS 12.2(15) and earlier fails to properly handle crafted TCP connections to the Telnet or reverse Telnet port, exhausting virtual terminal (VT…KEVEPSS 4.8%analysed10.0CVE-2021-44228Apache Log4j2 JNDI lookup remote code executionApache Log4j2 versions 2.0-beta9 through 2.15.0 (excluding 2.12.2, 2.12.3, and 2.3.1) do not protect against attacker-controlled LDAP and other JNDI …KEVEPSS 100%analysed8.6CVE-2020-3569Cisco IOS XR DVMRP IGMP packet handling memory exhaustionCisco IOS XR Software mishandles IGMP packets in its Distance Vector Multicast Routing Protocol (DVMRP) feature, allowing crafted traffic to crash th…KEVEPSS 3.3%analysed8.6CVE-2020-3566Cisco IOS XR DVMRP IGMP queue flaw causes memory exhaustionCisco IOS XR Software mishandles queue management for IGMP packets in its DVMRP feature, allowing uncontrolled memory consumption. An unauthenticated…KEVEPSS 3.7%analysed

Source: NIST National Vulnerability Database (record CVE-2026-59933), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.