{"answers":{"affected":"3 open source packages ship an affected version, including nltk.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81723 exists.","fix":"Upgrade nltk to 3.10.3 or later.","what":"CVE-2026-81723 is a medium-severity denial of service vulnerability in nltk, published on 27 Aug 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-2026-81723 and fix it if it is affected.\n\nWhat it is: CVE-2026-81723 is a medium-severity denial of service vulnerability in nltk, published on 27 Aug 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-2026-81723 exists.\n\nAffected packages and fixed versions:\n- nltk (PyPI): affected all versions; fixed in 3.10.3\n- nltk (PyPI): affected all versions; fixed in 3.10.3\n- nltk (PyPI): affected all versions; fixed in 3.10.3\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-2026-81723/ (Markdown: https://insights.sbomify.com/CVE-2026-81723/index.md)","id":"CVE-2026-81723","markdown":"https://insights.sbomify.com/CVE-2026-81723/index.md","name":"CVE-2026-81723","record":{"aliases":["DEBIAN-CVE-2026-81723","ECHO-3ec1-214e-209e","GHSA-vp2x-qp44-57v7","MINI-hvrv-3qj9-5jpj","PYSEC-2026-3871","UBUNTU-CVE-2026-81723"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Python NLP library","requires_auth":"none","summary":"Attackers can cause denial of service in NLTK by providing malformed XML files that trigger quadratic CPU exhaustion during parsing.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"NLTK versions before 3.10.3 contain a quadratic CPU exhaustion vulnerability in XMLCorpusView._read_xml_fragment() that rescans accumulated XML fragments on every 1 KiB block read. Attackers can provide malformed XML corpus files to cause severe CPU consumption and denial of service through affected readers like BNCCorpusReader.","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":"NLTK before 3.10.3 Quadratic CPU Exhaustion via XMLCorpusView","id":"CVE-2026-81723","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":3,"n_references":2,"next":{"headline":"NLTK before 3.10.3 Denial of Service via Uncontrolled Recursion","id":"CVE-2026-81724"},"packages":[{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":null,"source":"GHSA-vp2x-qp44-57v7"},{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"GHSA-vp2x-qp44-57v7"},{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"PYSEC-2026-3871"}],"prev":{"headline":"nltk PorterStemmer before 3.10.3 Quadratic-time DoS","id":"CVE-2026-81722"},"products":["nltk"],"published":"2026-08-27","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":"CC BY 4.0","name":"PyPA Advisory Database","prefix":"PYSEC"},{"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":"2026-08-31","vendors":["nltk"]},"summary":"Attackers can cause denial of service in NLTK by providing malformed XML files that trigger quadratic CPU exhaustion during parsing.","url":"https://insights.sbomify.com/CVE-2026-81723/"}