CVE-2026-108360 — PhpSpreadsheet: SSRF whitelist bypass via unre-validated HTTP redirect in Drawing::setPath external image loading
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Composer Phpoffice/phpspreadsheet: fixed in version 5.10.0 — github.com (GitHub Security Advisories)
- Composer Phpoffice/phpspreadsheet: fixed in version 3.10.8 — github.com (GitHub Security Advisories)
- Composer Phpoffice/phpspreadsheet: fixed in version 2.4.8 — github.com (GitHub Security Advisories)
- Composer Phpoffice/phpspreadsheet: fixed in version 2.1.19 — github.com (GitHub Security Advisories)
- Composer Phpoffice/phpspreadsheet: fixed in version 1.30.7 — github.com (GitHub Security Advisories)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Phpoffice Phpspreadsheet, Composer Phpoffice/phpspreadsheet).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Phpoffice | Phpspreadsheet | version < 1.30.7version >= 2.0.0, < 2.1.19version >= 2.2.0, < 2.4.8version >= 3.3.0, < 3.10.8version >= 4.0.0, < 5.10.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Composer | Phpoffice/phpspreadsheet | ≥ 4.0.0 and ≤ 5.9.0≥ 3.3.0 and ≤ 3.10.7≥ 2.2.0 and ≤ 2.4.7≥ 2.0.0 and ≤ 2.1.18≤ 1.30.6 | Vulnerable | GitHub Security Advisories |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.4 | CVSS 3.1 | Medium | 3.1 | 2.7 | security-advisories@github.com via NIST National Vulnerability Database |
| 6.4 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
| 6.4 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 23, 2026 → Oct 28, 2026 · 6 reading(s) · max 0.22%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · composer/phpoffice/phpspreadsheet
- SSVC assessment updated
- Source status changed · Received → Awaiting Analysis
- Affected products added · phpoffice/phpspreadsheet
- Record published
- CVSS changed · 6.4
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 22, 2026 – Oct 29, 2026
- 1× Official description updated · Oct 22, 2026 – Oct 22, 2026
References
13 on the record
- github.com/PHPOffice/PhpSpreadsheet/commit/299993894dce37aa3b64aa23e9a3f4bb77ab0
- github.com/advisories/GHSA-2phh-27fw-q4gc
- github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-2phh-27fw-q4gc
- github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.7
- github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8
- github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93
- github.com/PHPOffice/PhpSpreadsheet/commit/9a0b48622ebfe93fa48cb9bc09ce57303bb07
- github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0
- github.com/PHPOffice/PhpSpreadsheet/commit/da13f40e8760d599b0e8a296017d4b028b20e
- github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.8
- github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.19
- github.com/PHPOffice/PhpSpreadsheet/commit/94590951d76a250a5fc1ecf69a0b3f7439a9a
- nvd.nist.gov/vuln/detail/CVE-2026-108360
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-108357 PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service 6d
- High CVE-2026-108358 PhpSpreadsheet: XmlScanner Bypass via ISO-2022 Escape Sequences Allows XXE and Denial of Service 6d
- High CVE-2026-108359 PhpSpreadsheet ODS Reader: Unbounded number-rows-repeated → CPU & Memory Exhaustion (DoS) 6d
- High CVE-2026-59932 PhpSpreadsheet: Gnumeric reader unbounded gzip expansion causes memory exhaustion Jul 28, 2026
- High CVE-2026-59933 PhpSpreadsheet: XLS/OLE sector-chain self-loop causes memory exhaustion Jul 28, 2026
- High CVE-2026-59931 PhpSpreadsheet: SSRF bypass via HTTP redirect in WEBSERVICE() domain whitelist Jul 28, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-108360 is "PhpSpreadsheet: SSRF whitelist bypass via unre-validated HTTP redirect in Drawing::setPath external image loading", rated Medium. It affects Phpspreadsheet (Phpoffice); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.4 describes technical severity. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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