CVE-2026-108358
PhpSpreadsheet: XmlScanner Bypass via ISO-2022 Escape Sequences Allows XXE and Denial of Service
Description
PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0, XmlScanner::scan in src/PhpSpreadsheet/Reader/Security/XmlScanner.php uses a DOCTYPE detection pattern that accounts for NUL-byte interleaving but not ISO-2022 escape sequences in XLSX XML parts. The escape sequences prevent the scanner from matching the declaration, and XML charset normalization then removes the escape bytes before parsing, exposing a valid DOCTYPE and entity definitions. Processing an attacker-controlled XLSX can therefore cause entity-expansion denial of service on supported PHP versions and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0.
INFO
Published Date :
Oct. 22, 2026, 6:17 p.m.
Last Modified :
Oct. 22, 2026, 6:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update PhpSpreadsheet to 1.30.7 or later.
- Update PhpSpreadsheet to 2.1.19 or later.
- Update PhpSpreadsheet to 2.4.8 or later.
- Update PhpSpreadsheet to 3.10.8 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-108358.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-108358 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-108358
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-108358 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-108358 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Oct. 22, 2026
Action Type Old Value New Value Added Description PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0, XmlScanner::scan in src/PhpSpreadsheet/Reader/Security/XmlScanner.php uses a DOCTYPE detection pattern that accounts for NUL-byte interleaving but not ISO-2022 escape sequences in XLSX XML parts. The escape sequences prevent the scanner from matching the declaration, and XML charset normalization then removes the escape bytes before parsing, exposing a valid DOCTYPE and entity definitions. Processing an attacker-controlled XLSX can therefore cause entity-expansion denial of service on supported PHP versions and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-611 Added CWE CWE-776 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/108xxx/CVE-2026-108358.json">CVE-2026-108358</a> Added Reference https://github.com/PHPOffice/PhpSpreadsheet/commit/299993894dce37aa3b64aa23e9a3f4bb77ab0e66 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/commit/9a0b48622ebfe93fa48cb9bc09ce57303bb07af9 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/commit/da13f40e8760d599b0e8a296017d4b028b20e86c Added Reference https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.7 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.19 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.8 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0 Added Reference https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-3x94-m842-937c