{"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-2026-12261 exists.","fix":"Upgrade nltk to 3.10.0 or later.","what":"CVE-2026-12261 is a medium-severity missing authorization vulnerability in nltk/nltk, published on 7 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-2026-12261 and fix it if it is affected.\n\nWhat it is: CVE-2026-12261 is a medium-severity missing authorization vulnerability in nltk/nltk, published on 7 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-2026-12261 exists.\n\nAffected packages and fixed versions:\n- nltk (PyPI): affected all versions; fixed in 3.10.0\n- nltk (PyPI): affected all versions; fixed in 3.10.0\n- nltk (PyPI): affected all versions; fixed in 3.10.0\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-2026-12261/ (Markdown: https://insights.sbomify.com/CVE-2026-12261/index.md)","id":"CVE-2026-12261","markdown":"https://insights.sbomify.com/CVE-2026-12261/index.md","name":"CVE-2026-12261","record":{"aliases":["DEBIAN-CVE-2026-12261","ECHO-5b86-3218-603d","GHSA-ffj6-66c4-86gw","MINI-crj8-c9rg-7cf7","PYSEC-2026-3954","UBUNTU-CVE-2026-12261"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify","code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Python NLP library","requires_auth":"none","summary":"Attackers can poison shared NLTK resources by overwriting trusted models, potentially leading to code execution in downstream applications.","user_interaction":"required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"@huntr_ai","cpe":[{"product":"nltk","vendor":"nltk"}],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","version":"3.0"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"}],"description":"A vulnerability in `nltk.downloader` in nltk/nltk versions \u003c= 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package archives into shared namespaces such as `corpora/` and `taggers/` instead of package-isolated roots, and validates package integrity only after the archive has been written and extracted. This design flaw enables one package to overwrite another package's trusted resources within the same namespace, making the changes immediately active through ordinary NLTK APIs. This issue persists across fresh interpreter restarts and can affect downstream workflows, including machine learning pipelines and reproducibility-sensitive environments.","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":"Improper Access Control in nltk/nltk","id":"CVE-2026-12261","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"missing_authorization","year":"2026"},"n_packages":3,"n_references":1,"next":{"headline":"Authentication Bypass","id":"CVE-2026-12263"},"packages":[{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":null,"source":"GHSA-ffj6-66c4-86gw"},{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"GHSA-ffj6-66c4-86gw"},{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"PYSEC-2026-3954"}],"prev":{"headline":"SQL injection in the NetBoard CRM demo platform","id":"CVE-2026-12260"},"products":["nltk/nltk"],"published":"2026-08-07","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":"2026-08-07","vendors":["nltk"]},"summary":"Attackers can poison shared NLTK resources by overwriting trusted models, potentially leading to code execution in downstream applications.","url":"https://insights.sbomify.com/CVE-2026-12261/"}