{"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-2026-59928 exists.","fix":"Upgrade mistune to 3.3.0 or later.","what":"CVE-2026-59928 is a high-severity denial of service vulnerability in lepture mistune, published on 8 Jul 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-2026-59928 and fix it if it is affected.\n\nWhat it is: CVE-2026-59928 is a high-severity denial of service vulnerability in lepture mistune, published on 8 Jul 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-2026-59928 exists.\n\nAffected packages and fixed versions:\n- mistune (PyPI): affected all versions; fixed in 3.3.0\n- mistune (PyPI): affected all versions; fixed in 3.3.0\n- mistune (PyPI): affected all versions; fixed in 3.3.0\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-2026-59928/ (Markdown: https://insights.sbomify.com/CVE-2026-59928/index.md)","id":"CVE-2026-59928","markdown":"https://insights.sbomify.com/CVE-2026-59928/index.md","name":"CVE-2026-59928","record":{"aliases":["AZL-92211","DEBIAN-CVE-2026-59928","ECHO-059a-fd72-cb55","GHSA-ffq3-xpv3-j92q","PYSEC-2026-2216","UBUNTU-CVE-2026-59928"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Python Markdown parser","requires_auth":"none","summary":"An attacker can cause CPU exhaustion and denial of service by submitting Markdown documents with many repeated reference-link definitions to applications using Mistune.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mistune","vendor":"mistune_project"}],"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-407","name":"Inefficient Algorithmic Complexity"},{"id":"CWE-1333","name":"Inefficient Regular Expression Complexity"}],"description":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.","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 block_parser: quadratic-time parsing on long lists of repeated reference-link definitions","id":"CVE-2026-59928","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"Mistune renderers/html.safe_url: HARMFUL_PROTOCOLS list misses legacy and chained schemes that historically chain to `javascript:` execution","id":"CVE-2026-59929"},"packages":[{"ecosystem":"PyPI","fixed":["3.3.0"],"introduced":["0"],"last_affected":[],"package":"mistune","purl":null,"source":"GHSA-ffq3-xpv3-j92q"},{"ecosystem":"PyPI","fixed":["3.3.0"],"introduced":["0"],"last_affected":[],"package":"mistune","purl":"pkg:pypi/mistune","source":"GHSA-ffq3-xpv3-j92q"},{"ecosystem":"PyPI","fixed":["3.3.0"],"introduced":["0"],"last_affected":[],"package":"mistune","purl":"pkg:pypi/mistune","source":"PYSEC-2026-2216"}],"prev":{"headline":"Mistune directives/include: mutual `.. include::` recursion crashes the renderer with `RecursionError`, denial of service via two attacker-controlled markdown files","id":"CVE-2026-59927"},"products":["mistune"],"published":"2026-07-08","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":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":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-08","vendors":["lepture"]},"summary":"An attacker can cause CPU exhaustion and denial of service by submitting Markdown documents with many repeated reference-link definitions to applications using Mistune.","url":"https://insights.sbomify.com/CVE-2026-59928/"}