phpoffice/phpspreadsheet security advisory

CVE-2026-108360: PhpSpreadsheet: SSRF whitelist bypass via unre-validated HTTP redirect in Drawing::setPath external image loading

CVE-2026-108360 is a medium-severity SSRF vulnerability in the PHP package phpoffice/phpspreadsheet (CVSS 6.4), published 22 October 2026. The advisory does not name a fixed version. Exploiting it needs a low-privilege user account.

medium 6.4 published 2026-10-22 · updated 2026-10-29

Affected versions: <= 1.30.6
>= 2.0.0, <= 2.1.18
>= 2.2.0, <= 2.4.7
>= 3.3.0, <= 3.10.7
>= 4.0.0, <= 5.9.0
Fixed in: not stated
Newest release: 5.10.0
Severity: Medium · CVSS 6.4
Type: Server-side request forgery (SSRF)
CWE-863, CWE-918
Exploited in the wild: Not on the CISA KEV list
checked 2026-11-04

Is your phpoffice/phpspreadsheet version affected?

Run composer show phpoffice/phpspreadsheet in your project, then enter the version. We check it against this and every other known phpoffice/phpspreadsheet advisory.

Who can exploit CVE-2026-108360

Access: A normal, low-privilege user account in the app.

CVSS vector (scored by GitHub): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Your app is only exposed if it uses the affected part of phpoffice/phpspreadsheet. The advisory below says which part that is. If you are not sure, upgrade anyway: it costs less than finding out.

How to fix CVE-2026-108360 in phpoffice/phpspreadsheet

Find the installed version: composer show phpoffice/phpspreadsheet. If you never required it yourself, composer why phpoffice/phpspreadsheet shows which package pulls it in.
Update it: composer update phpoffice/phpspreadsheet --with-all-dependencies.
If Composer will not go that high, your composer.json constraint is holding it back. Widen it (for example "phpoffice/phpspreadsheet": "^5.10.0" if you can take that version), or upgrade the package that requires it.
Run composer audit. It reads the same advisory data and should no longer list CVE-2026-108360.
Commit composer.lock and deploy it. On the server, run composer install --no-dev from the lock file, not composer update.

If you cannot upgrade yet

General hardening for SSRF issues while the upgrade waits. None of it replaces the fix.

Block outbound requests from the app server to private ranges and cloud metadata (169.254.169.254) at the firewall.
Do not pass user-supplied URLs to the affected feature.
If your app does not use the affected feature, note that in your audit, but still plan the upgrade.

The CVE-2026-108360 advisory

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.

Description from the CVE record, published by GitHub (the CVE Numbering Authority), via the NVD entry for CVE-2026-108360. Advisory title: “PhpSpreadsheet: SSRF whitelist bypass via unre-validated HTTP redirect in Drawing::setPath external image loading”.

References

GitHub advisory GHSA-2phh-27fw-q4gc github.com
Fix commit 2999938 github.com
Fix commit 9459095 github.com
Fix commit 980b5c2 github.com
Fix commit 9a0b486 github.com
Fix commit da13f40 github.com
Release 1.30.7 github.com
Release 2.1.19 github.com

Other phpoffice/phpspreadsheet advisories

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Where this data comes from

Affected and fixed versions: the Packagist security advisories API (GitHub Advisory Database and FriendsOfPHP), the same data composer audit uses. Synced 2026-11-03.
Description, score, weakness and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Exploited-in-the-wild status: the CISA Known Exploited Vulnerabilities catalog, checked 2026-11-04.
Compiled by Daniel Lasek at Laskyr from the sources above. The summary, “who can exploit it”, “how to fix it” and hardening sections are our plain-English reading of the record and are generated from it. The quoted description is the record's own text. Spot an error? Tell us.