{"answers":{"affected":"3 open source packages ship an affected version, including nltk. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81727 exists.","fix":"Upgrade nltk to 3.10.3 or later.","what":"CVE-2026-81727 is a medium-severity path traversal vulnerability in nltk, published on 27 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-81727 and fix it if it is affected.\n\nWhat it is: CVE-2026-81727 is a medium-severity path traversal vulnerability in nltk, published on 27 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81727 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-2026-81727/ (Markdown: https://insights.sbomify.com/CVE-2026-81727/index.md)","id":"CVE-2026-81727","markdown":"https://insights.sbomify.com/CVE-2026-81727/index.md","name":"CVE-2026-81727","record":{"aliases":["DEBIAN-CVE-2026-81727","ECHO-d083-fbc5-4389","GHSA-f794-5jv7-7672","MINI-6v5c-8qhh-9c24","PYSEC-2026-3741","UBUNTU-CVE-2026-81727"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Python NLP library","requires_auth":"low_privilege","summary":"Attackers with write access to a shared directory can overwrite arbitrary files outside the install root via hardlinks during NLTK package downloads.","user_interaction":"not_required","vuln_class":"path_traversal"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[{"product":"nltk","vendor":"nltk"}],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-59","name":"Improper Link Resolution Before File Access"}],"description":"NLTK versions before 3.10.3 contain a filesystem containment bypass vulnerability in the Downloader.download and Downloader.incr_download methods that allows attackers to overwrite files outside the install root through pre-existing hardlinks. Attackers with write access to a shared downloader directory can create hardlinks pointing to outside-root files that are then overwritten during normal package extraction, mutating files outside the intended install tree.","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 Hardlink File Overwrite via downloader","id":"CVE-2026-81727","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"path_traversal","year":"2026"},"n_packages":3,"n_references":2,"next":{"headline":"Dolibarr before 24.0.0 SQL Injection via the CSV and XLSX Import Update Keys","id":"CVE-2026-81728"},"packages":[{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":null,"source":"GHSA-f794-5jv7-7672"},{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"GHSA-f794-5jv7-7672"},{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"PYSEC-2026-3741"}],"prev":{"headline":"NLTK through 3.10.3 Path Traversal via Model-Artifact APIs","id":"CVE-2026-81726"},"products":["nltk"],"published":"2026-08-27","related":[{"cvss_score":10,"headline":"Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading","id":"CVE-2026-0848","kev_date_added":null,"published":"2026-03-05"},{"cvss_score":10,"headline":"Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution","id":"CVE-2025-14009","kev_date_added":null,"published":"2026-02-18"},{"cvss_score":9.4,"headline":"NLTK before 3.10.0 Remote Code Execution via Unsafe Pickle Deserialization","id":"CVE-2026-78683","kev_date_added":null,"published":"2026-08-25"},{"cvss_score":9.3,"headline":"NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization","id":"CVE-2026-79657","kev_date_added":null,"published":"2026-08-25"},{"cvss_score":9.3,"headline":"NLTK before 3.10.3 JVM Argument Injection via Per-Call Options","id":"CVE-2026-79675","kev_date_added":null,"published":"2026-08-25"},{"cvss_score":8.8,"headline":"NLTK 3.10.2 Path Traversal via corpus-reader constructors","id":"CVE-2026-79674","kev_date_added":null,"published":"2026-08-25"},{"cvss_score":8.7,"headline":"nltk PorterStemmer before 3.10.3 Quadratic-time DoS","id":"CVE-2026-81722","kev_date_added":null,"published":"2026-08-27"}],"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":"2026-08-27","vendors":["nltk"]},"summary":"Attackers with write access to a shared directory can overwrite arbitrary files outside the install root via hardlinks during NLTK package downloads.","url":"https://insights.sbomify.com/CVE-2026-81727/"}