{"answers":{"affected":"10 open source packages ship an affected version, including phpoffice/phpspreadsheet. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40863 exists.","fix":"Upgrade phpoffice/phpspreadsheet to a fixed version for your release line: 1.30.6, 2.1.16, 2.4.5 or 3.10.5.","what":"CVE-2026-40863 is a high-severity denial of service vulnerability in PHPOffice PhpSpreadsheet, published on 12 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-40863 and fix it if it is affected.\n\nWhat it is: CVE-2026-40863 is a high-severity denial of service vulnerability in PHPOffice PhpSpreadsheet, published on 12 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40863 exists.\n\nAffected packages and fixed versions:\n- phpoffice/phpspreadsheet (Packagist): affected all versions; fixed in 1.30.6\n- phpoffice/phpspreadsheet (Packagist): affected all versions; fixed in 1.30.6\n- phpoffice/phpspreadsheet (Packagist): affected from 2.0.0; fixed in 2.1.16\n- phpoffice/phpspreadsheet (Packagist): affected from 2.0.0; fixed in 2.1.16\n- phpoffice/phpspreadsheet (Packagist): affected from 2.2.0; fixed in 2.4.5\n- phpoffice/phpspreadsheet (Packagist): affected from 2.2.0; fixed in 2.4.5\n- phpoffice/phpspreadsheet (Packagist): affected from 3.3.0; fixed in 3.10.5\n- phpoffice/phpspreadsheet (Packagist): affected from 3.3.0; fixed in 3.10.5\n- phpoffice/phpspreadsheet (Packagist): affected from 4.0.0; fixed in 5.7.0\n- phpoffice/phpspreadsheet (Packagist): affected from 4.0.0; fixed in 5.7.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-40863/ (Markdown: https://insights.sbomify.com/CVE-2026-40863/index.md)","id":"CVE-2026-40863","markdown":"https://insights.sbomify.com/CVE-2026-40863/index.md","name":"CVE-2026-40863","record":{"aliases":["GHSA-84wq-86v6-x5j6"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"PHP spreadsheet library","requires_auth":"none","summary":"Attackers can cause CPU exhaustion and denial of service by crafting malicious SpreadsheetML XML files with unbounded row indices in PhpSpreadsheet.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"phpspreadsheet","vendor":"phpoffice"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0, the SpreadsheetML XML reader (Reader\\Xml) does not validate the ss:Index row attribute against the maximum allowed row count (AddressRange::MAX_ROW = 1,048,576). An attacker can craft a SpreadsheetML XML file with ss:Index=\"999999999\" on a \u003cRow\u003e element, which inflates the internal cachedHighestRow to ~1 billion. Any subsequent call to getRowIterator() without an explicit end row will attempt to iterate ~1 billion rows, causing CPU exhaustion and denial of service. This vulnerability is fixed in 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0.","ecosystems":["Packagist"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"PhpSpreadsheet: CPU Denial of Service via Unbounded Row Index in SpreadsheetML XML Reader","id":"CVE-2026-40863","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Packagist","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":10,"n_references":1,"next":{"headline":"JupyterHub: Cross-origin form POSTs bypass XSRF","id":"CVE-2026-40864"},"packages":[{"ecosystem":"Packagist","fixed":["1.30.6"],"introduced":["0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":null,"source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["1.30.6"],"introduced":["0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":"pkg:composer/phpoffice/phpspreadsheet","source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["2.1.16"],"introduced":["2.0.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":null,"source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["2.1.16"],"introduced":["2.0.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":"pkg:composer/phpoffice/phpspreadsheet","source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["2.4.5"],"introduced":["2.2.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":null,"source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["2.4.5"],"introduced":["2.2.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":"pkg:composer/phpoffice/phpspreadsheet","source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["3.10.5"],"introduced":["3.3.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":null,"source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["3.10.5"],"introduced":["3.3.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":"pkg:composer/phpoffice/phpspreadsheet","source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["5.7.0"],"introduced":["4.0.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":null,"source":"GHSA-84wq-86v6-x5j6"},{"ecosystem":"Packagist","fixed":["5.7.0"],"introduced":["4.0.0"],"last_affected":[],"package":"phpoffice/phpspreadsheet","purl":"pkg:composer/phpoffice/phpspreadsheet","source":"GHSA-84wq-86v6-x5j6"}],"prev":{"headline":"Apache Airflow: Arbitrary File Read via Log Symlink following in FileTaskHandler","id":"CVE-2026-40861"},"products":["PhpSpreadsheet"],"published":"2026-05-12","related":[{"cvss_score":9.2,"headline":"PhpSpreadsheet SSRF and RCE via PHP stream wrappers in IOFactory::load","id":"CVE-2026-34084","kev_date_added":null,"published":"2026-05-05"},{"cvss_score":8.8,"headline":"XML External Entity Reference (XXE) in PHPSpreadsheet","id":"CVE-2024-45048","kev_date_added":null,"published":"2024-08-28"},{"cvss_score":8.8,"headline":"XXE in PHPSpreadsheet due to incomplete fix for previous encoding issue","id":"CVE-2019-12331","kev_date_added":null,"published":"2019-11-07"},{"cvss_score":8.8,"headline":"XXE in PHPSpreadsheet due to encoding issue","id":"CVE-2018-19277","kev_date_added":null,"published":"2018-11-14"},{"cvss_score":8.3,"headline":"PhpSpreadsheet vulnerable to unauthorized reflected XSS in the constructor of the Downloader class","id":"CVE-2024-56365","kev_date_added":null,"published":"2025-01-03"},{"cvss_score":8.3,"headline":"PhpSpreadsheet vulnerable to unauthorized reflected XSS in the Accounting.php file","id":"CVE-2024-56366","kev_date_added":null,"published":"2025-01-03"},{"cvss_score":8.3,"headline":"PhpSpreadsheet allows unauthorized reflected XSS in `Convert-Online.php` file","id":"CVE-2024-56408","kev_date_added":null,"published":"2025-01-03"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-13","vendors":["PHPOffice"]},"summary":"Attackers can cause CPU exhaustion and denial of service by crafting malicious SpreadsheetML XML files with unbounded row indices in PhpSpreadsheet.","url":"https://insights.sbomify.com/CVE-2026-40863/"}