CVE-2026-108360
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AI Threat Summary
CVE-2026-108360 is a moderate vulnerability with a CVSS score of 6.4 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
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, Worksheet\Drawing::setPath validates only the initial external-image URL with setIsWhitelisted when setAllowExternalImages is enabled. The HTTP stream context permits PHP to follow a redirect without applying the callback to the redirected URL, so a permitted image host can redirect the server to an internal address and cause a blind GET request. The response body is not returned to the attacker because the reader validates the downloaded content as an image and removes the temporary file, but internal GET-driven endpoints, network reachability, and cloud metadata endpoints may be reached. This issue is fixed in versions 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0.
Attack Chain
Attacker scans for vulnerable versions using version banners or PoC scanners
Attacker triggers CVE-2026-108360 vulnerability with a crafted request or payload
Vulnerability exploited to perform unauthorized actions on the target system
Depending on vulnerability type, attacker achieves data access, service disruption, or code execution
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-108360 |
| CVSS Score | 6.4 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| Published | 2026-10-22 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://github.com/PHPOffice/PhpSpreadsheet/commit/299993894…
- https://github.com/PHPOffice/PhpSpreadsheet/commit/94590951d…
- https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294…
- https://github.com/PHPOffice/PhpSpreadsheet/commit/9a0b48622…
- https://github.com/PHPOffice/PhpSpreadsheet/commit/da13f40e8…
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.3…
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1…
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4…
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.1…
- https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.1…