{"answers":{"affected":"2 open source packages ship an affected version, including justhtml.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5389 exists.","fix":"Upgrade justhtml to 1.13.0 or later.","what":"CVE-2026-5389 is a medium-severity cross-site scripting vulnerability in EmilStenstrom justhtml, published on 23 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-5389 and fix it if it is affected.\n\nWhat it is: CVE-2026-5389 is a medium-severity cross-site scripting vulnerability in EmilStenstrom justhtml, published on 23 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5389 exists.\n\nAffected packages and fixed versions:\n- justhtml (PyPI): affected all versions; fixed in 1.13.0\n- justhtml (PyPI): affected all versions; fixed in 1.13.0\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-2026-5389/ (Markdown: https://insights.sbomify.com/CVE-2026-5389/index.md)","id":"CVE-2026-5389","markdown":"https://insights.sbomify.com/CVE-2026-5389/index.md","name":"CVE-2026-5389","record":{"aliases":["GHSA-5vp3-3cg6-2rq3","GHSA-q3jf-9wv7-p29w"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"HTML sanitization library","requires_auth":"none","summary":"Attackers can inject raw HTML into sanitized content via code fence breakout, leading to XSS when rendered by Markdown parsers.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-80","name":"Improper Neutralization of Script-Related HTML Tags in a Web Page"}],"description":"justhtml versions before 1.13.0 contain a cross-site scripting vulnerability in the to_markdown() function when serializing attacker-controlled pre content. Attackers can place backticks inside sanitized pre elements to break out of fixed-length code fences, allowing raw HTML to execute when the generated Markdown is rendered by CommonMark or GFM-style renderers.","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":false,"headline":"justhtml before 1.13.0 XSS via code fence breakout","id":"CVE-2026-5389","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":2,"n_references":2,"next":{"headline":"LatePoint \u003c= 5.3.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes","id":"CVE-2026-5391"},"packages":[{"ecosystem":"PyPI","fixed":["1.13.0"],"introduced":["0"],"last_affected":[],"package":"justhtml","purl":null,"source":"GHSA-5vp3-3cg6-2rq3"},{"ecosystem":"PyPI","fixed":["1.13.0"],"introduced":["0"],"last_affected":[],"package":"justhtml","purl":"pkg:pypi/justhtml","source":"GHSA-5vp3-3cg6-2rq3"}],"prev":{"headline":"justhtml before 1.15.0 Multiple Security Issues","id":"CVE-2026-5388"},"products":["justhtml"],"published":"2026-08-23","related":[],"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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-24","vendors":["EmilStenstrom"]},"summary":"Attackers can inject raw HTML into sanitized content via code fence breakout, leading to XSS when rendered by Markdown parsers.","url":"https://insights.sbomify.com/CVE-2026-5389/"}