{"answers":{"affected":"2 open source packages ship an affected version, including league/commonmark. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-30838 in the wild and no public exploit code.","fix":"Upgrade league/commonmark to 2.8.1 or later.","what":"CVE-2026-30838 is a medium-severity cross-site scripting vulnerability in thephpleague commonmark, published on 7 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-30838 and fix it if it is affected.\n\nWhat it is: CVE-2026-30838 is a medium-severity cross-site scripting vulnerability in thephpleague commonmark, published on 7 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-30838 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- league/commonmark (Packagist): affected from 2.0.0; fixed in 2.8.1\n- league/commonmark (Packagist): affected from 2.0.0; fixed in 2.8.1\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-2026-30838/ (Markdown: https://insights.sbomify.com/CVE-2026-30838/index.md)","id":"CVE-2026-30838","markdown":"https://insights.sbomify.com/CVE-2026-30838/index.md","name":"CVE-2026-30838","record":{"aliases":["CLSA-2026-1776731783","DEBIAN-CVE-2026-30838","GHSA-4v6x-c7xx-hw9f","UBUNTU-CVE-2026-30838"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"PHP Markdown parser","requires_auth":"low_privilege","summary":"Attackers can bypass HTML sanitization in league/commonmark to inject malicious scripts via whitespace in tag names, leading to XSS.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"commonmark","vendor":"thephpleague"}],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"league/commonmark is a PHP Markdown parser. Prior to version 2.8.1, the DisallowedRawHtml extension can be bypassed by inserting a newline, tab, or other ASCII whitespace character between a disallowed HTML tag name and the closing \u003e. For example, \u003cscript\\n\u003e would pass through unfiltered and be rendered as a valid HTML tag by browsers. This is a cross-site scripting (XSS) vector for any application that relies on this extension to sanitize untrusted user input. All applications using the DisallowedRawHtml extension to process untrusted markdown are affected. Applications that use a dedicated HTML sanitizer (such as HTML Purifier) on the rendered output are not affected. This issue has been patched in version 2.8.1.","ecosystems":["Packagist"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"league/commonmark: DisallowedRawHtml extension bypass via whitespace in HTML tag names","id":"CVE-2026-30838","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Packagist","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":2,"n_references":1,"next":{"headline":"Wallos: SSRF via webhook test endpoint","id":"CVE-2026-30839"},"packages":[{"ecosystem":"Packagist","fixed":["2.8.1"],"introduced":["2.0.0"],"last_affected":[],"package":"league/commonmark","purl":null,"source":"GHSA-4v6x-c7xx-hw9f"},{"ecosystem":"Packagist","fixed":["2.8.1"],"introduced":["2.0.0"],"last_affected":[],"package":"league/commonmark","purl":"pkg:composer/league/commonmark","source":"GHSA-4v6x-c7xx-hw9f"}],"prev":{"headline":"Elysia has a string URL format redos","id":"CVE-2026-30837"},"products":["commonmark"],"published":"2026-03-07","related":[{"cvss_score":8.7,"headline":"commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes","id":"CVE-2026-86428","kev_date_added":null,"published":"2026-09-07"},{"cvss_score":8.7,"headline":"commonmark before 2.9.1 Denial of Service via SmartPunct and Attributes","id":"CVE-2026-86429","kev_date_added":null,"published":"2026-09-07"},{"cvss_score":8.7,"headline":"league/commonmark before 2.9.1 Denial of Service via parsing","id":"CVE-2026-86430","kev_date_added":null,"published":"2026-09-07"},{"cvss_score":6.9,"headline":"commonmark before 2.9.1 XSS via AttributesExtension form feed bypass","id":"CVE-2026-86431","kev_date_added":null,"published":"2026-09-07"},{"cvss_score":6.3,"headline":"league/commonmark has an embed extension allowed_domains bypass","id":"CVE-2026-33347","kev_date_added":null,"published":"2026-03-24"},{"cvss_score":6.1,"headline":"Moderate severity vulnerability that affects league/commonmark","id":"CVE-2019-10010","kev_date_added":null,"published":"2019-03-24"},{"cvss_score":6.1,"headline":"PHP League CommonMark vulnerable to Cross-Site Scripting (XSS)","id":"CVE-2018-20583","kev_date_added":null,"published":"2018-12-30"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-03-09","vendors":["thephpleague"]},"summary":"Attackers can bypass HTML sanitization in league/commonmark to inject malicious scripts via whitespace in tag names, leading to XSS.","url":"https://insights.sbomify.com/CVE-2026-30838/"}