{"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-2026-86428 in the wild and no public exploit code.","fix":"Upgrade league/commonmark to 2.10.0 or later.","what":"CVE-2026-86428 is a high-severity denial of service vulnerability in thephpleague commonmark, published on 7 Sep 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-2026-86428 and fix it if it is affected.\n\nWhat it is: CVE-2026-86428 is a high-severity denial of service vulnerability in thephpleague commonmark, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-86428 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- league/commonmark (Packagist): affected from 1.5.0; fixed in 2.10.0\n- league/commonmark (Packagist): affected from 1.5.0; fixed in 2.10.0\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-2026-86428/ (Markdown: https://insights.sbomify.com/CVE-2026-86428/index.md)","id":"CVE-2026-86428","markdown":"https://insights.sbomify.com/CVE-2026-86428/index.md","name":"CVE-2026-86428","record":{"aliases":["DEBIAN-CVE-2026-86428","GHSA-8h74-w38m-j62j","GHSA-8rr7-cvq3-gmfh","UBUNTU-CVE-2026-86428"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"PHP Markdown library","requires_auth":"none","summary":"Attackers can cause denial of service in the commonmark library by submitting Markdown with numerous distinct attribute names, leading to excessive CPU consumption.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[{"product":"commonmark","vendor":"thephpleague"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-407","name":"Inefficient Algorithmic Complexity"}],"description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","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":"commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes","id":"CVE-2026-86428","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Packagist","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":2,"n_references":2,"next":{"headline":"commonmark before 2.9.1 Denial of Service via SmartPunct and Attributes","id":"CVE-2026-86429"},"packages":[{"ecosystem":"Packagist","fixed":["2.10.0"],"introduced":["1.5.0"],"last_affected":[],"package":"league/commonmark","purl":null,"source":"GHSA-8rr7-cvq3-gmfh"},{"ecosystem":"Packagist","fixed":["2.10.0"],"introduced":["1.5.0"],"last_affected":[],"package":"league/commonmark","purl":"pkg:composer/league/commonmark","source":"GHSA-8rr7-cvq3-gmfh"}],"prev":{"headline":"LibreNMS before 26.8.0 Argument Injection via graph_title","id":"CVE-2026-86427"},"products":["commonmark"],"published":"2026-09-07","related":[{"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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-08","vendors":["thephpleague"]},"summary":"Attackers can cause denial of service in the commonmark library by submitting Markdown with numerous distinct attribute names, leading to excessive CPU consumption.","url":"https://insights.sbomify.com/CVE-2026-86428/"}