{"answers":{"affected":"3 open source packages ship an affected version, including mistune. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44899 exists.","fix":"Upgrade mistune to 3.2.1 or later.","what":"CVE-2026-44899 is a medium-severity cross-site scripting vulnerability in lepture mistune, published on 26 May 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-2026-44899 and fix it if it is affected.\n\nWhat it is: CVE-2026-44899 is a medium-severity cross-site scripting vulnerability in lepture mistune, published on 26 May 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-2026-44899 exists.\n\nAffected packages and fixed versions:\n- mistune (PyPI): affected all versions; fixed in 3.2.1\n- mistune (PyPI): affected from 3.2.0; fixed in 3.2.1\n- mistune (PyPI): affected from 3.2.0; fixed in 3.2.1\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-2026-44899/ (Markdown: https://insights.sbomify.com/CVE-2026-44899/index.md)","id":"CVE-2026-44899","markdown":"https://insights.sbomify.com/CVE-2026-44899/index.md","name":"CVE-2026-44899","record":{"aliases":["AZL-88406","CLEANSTART-2026-OL63472","CLEANSTART-2026-SI19530","DEBIAN-CVE-2026-44899","GHSA-ccfx-mfmx-2fx9","PYSEC-2026-2209","UBUNTU-CVE-2026-44899"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Python Markdown parser","requires_auth":"none","summary":"An attacker can inject malicious CSS into image directives, potentially leading to cross-site scripting attacks in applications using the Mistune library.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mistune","vendor":"mistune_project"}],"cvss":{"score":4.7,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, the Image directive plugin validates the :width: and :height: options with a regex compiled as _num_re = re.compile(r\"^\\d+(?:\\.\\d*)?\"). When the validated value is not a plain integer, render_block_image() inserts it directly into a style=\"width:...;\" or style=\"height:...;\" attribute. Because the value was accepted by the prefix-only regex, any CSS after the leading digits reaches the style= attribute verbatim and without escaping. This vulnerability is fixed in 3.2.1.","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"Mistune Image Directive CSS Injection Vulnerability","id":"CVE-2026-44899","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":3,"n_references":2,"next":{"headline":"epa4all-client: VAU Signature bypass","id":"CVE-2026-44900"},"packages":[{"ecosystem":"PyPI","fixed":["3.2.1"],"introduced":["0"],"last_affected":[],"package":"mistune","purl":"pkg:pypi/mistune","source":"PYSEC-2026-2209"},{"ecosystem":"PyPI","fixed":["3.2.1"],"introduced":["3.2.0"],"last_affected":[],"package":"mistune","purl":null,"source":"GHSA-ccfx-mfmx-2fx9"},{"ecosystem":"PyPI","fixed":["3.2.1"],"introduced":["3.2.0"],"last_affected":[],"package":"mistune","purl":"pkg:pypi/mistune","source":"GHSA-ccfx-mfmx-2fx9"}],"prev":{"headline":"Mistune TOC Anchor Injection XSS","id":"CVE-2026-44898"},"products":["mistune"],"published":"2026-05-26","related":[{"cvss_score":7.5,"headline":"Mistune plugins/formatting: quadratic-time parsing on long runs of `~~x~~`, `==x==`, and `^^x^^` markers (strikethrough / mark / insert)","id":"CVE-2026-59922","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":7.5,"headline":"inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs","id":"CVE-2026-59925","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":7.5,"headline":"Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions","id":"CVE-2026-59928","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":6.1,"headline":"Mistune: XSS via percent-encoded javascript URI bypass in safe_url()","id":"CVE-2026-59923","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":6.1,"headline":"Mistune renderers/html.safe_url: HARMFUL_PROTOCOLS list misses legacy and chained schemes that historically chain to `javascript:` execution","id":"CVE-2026-59929","kev_date_added":null,"published":"2026-07-08"},{"cvss_score":6.1,"headline":"Mistune Math Plugin XSS Escape Bypass","id":"CVE-2026-44708","kev_date_added":null,"published":"2026-05-26"},{"cvss_score":6.1,"headline":"Mistune Heading ID Attribute Injection XSS","id":"CVE-2026-44897","kev_date_added":null,"published":"2026-05-26"}],"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":"CC BY 4.0","name":"PyPA Advisory Database","prefix":"PYSEC"},{"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":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-27","vendors":["lepture"]},"summary":"An attacker can inject malicious CSS into image directives, potentially leading to cross-site scripting attacks in applications using the Mistune library.","url":"https://insights.sbomify.com/CVE-2026-44899/"}