PHPSpreadsheet: SSRF bypass via HTTP redirect in WEBSERVICE() domain whitelist

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-59931: 0.47% estimated exploitation activity in the next 30 days; percentile 41.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The domain whitelist introduced in PhpSpreadsheet 5.4.0 for the WEBSERVICE() formula function can be bypassed via HTTP redirect. The whitelist validates only the initial URL's hostname, but filegetcontents() follows 302/301 redirects by default without re-validating the redirect target against the whitelist. This allows an attacker to reach internal services through a whitelisted domain that issues an HTTP redirect. Details In Calculation/Web/Service.php, the webService() method validates the URL's host against a domain whitelist set via Spreadsheet::setDomainWhiteList(). If the host passes validation, the method calls filegetcontents($url, false, $ctx) to fetch the content. The stream context does not disable redirect following: PHP's HTTP stream wrapper follows redirects automatically (up to 20 hops by default). The redirect target URL is not re-validated against the domain whitelist. An attacker who can trigger a 302 redirect from a whitelisted domain can redirect the…

Published by the source

23 Jul 2026, 14:55 UTC

Last modified by the source

23 Jul 2026, 14:55 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6hq5-7373-42rg

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# Patch Next advisory brief: CVE-2026-59931

Advisory: PHPSpreadsheet: SSRF bypass via HTTP redirect in WEBSERVICE() domain whitelist
IDs: CVE-2026-59931, GHSA-6hq5-7373-42rg
Record: https://patchnext.com/advisories/cve-2026-59931 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: phpoffice/phpspreadsheet 5.8.1, 3.10.7, 2.4.7, 2.1.18, 1.30.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist phpoffice/phpspreadsheet: affected >= 4.0.0, <= 5.8.0; >= 3.3.0, <= 3.10.6; >= 2.2.0, <= 2.4.6; >= 2.0.0, <= 2.1.17; <= 1.30.5; fixed in 2.1.18, 3.10.7, 2.4.7, 1.30.6, 5.8.1

## Suggested inspection (read-only)
- Packagist phpoffice/phpspreadsheet: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on phpoffice/phpspreadsheet.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6hq5-7373-42rg (GitHub-reviewed advisory GHSA-6hq5-7373-42rg lists affected ranges: Packagist phpoffice/phpspreadsheet >=4.0.0 =3.3.0 =2.2.0 =2.0.0 =0 <=1.30.5)

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