{"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-2026-78683 exists.","fix":"Upgrade nltk to 3.10.0 or later.","what":"CVE-2026-78683 is a critical unsafe deserialization vulnerability in nltk, published on 25 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-2026-78683 and fix it if it is affected.\n\nWhat it is: CVE-2026-78683 is a critical unsafe deserialization vulnerability in nltk, published on 25 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-2026-78683 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-2026-78683/ (Markdown: https://insights.sbomify.com/CVE-2026-78683/index.md)","id":"CVE-2026-78683","markdown":"https://insights.sbomify.com/CVE-2026-78683/index.md","name":"CVE-2026-78683","record":{"aliases":["DEBIAN-CVE-2026-78683","ECHO-4f4f-fb61-1650","GHSA-rhp5-r9x4-f5g2","MINI-hmvw-744c-g4rh","PYSEC-2026-3734"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Python NLP library","requires_auth":"none","summary":"Attackers can execute arbitrary code by tricking applications into loading malicious model files via unsafe pickle deserialization in NLTK.","user_interaction":"required","vuln_class":"deserialization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[{"product":"nltk","vendor":"nltk"}],"cvss":{"score":9.4,"severity":"critical","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","version":"4.0"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"description":"NLTK before 3.10.0 (affected versions \u003c=3.9.4) contains an unsafe pickle deserialization vulnerability in the TransitionParser.parse() method (nltk/parse/transitionparser.py). The method calls pickle_load() with the default restricted=False, routing deserialization through WarningUnpickler, which does not override find_class() and therefore permits arbitrary class resolution. When an application loads an attacker-crafted model file, embedded pickle gadget chains execute arbitrary Python code with the privileges of the user running the application. NLTK provides a RestrictedUnpickler for safe deserialization, but it is not used by production code paths. Fixed in 3.10.0.","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":"NLTK before 3.10.0 Remote Code Execution via Unsafe Pickle Deserialization","id":"CVE-2026-78683","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"deserialization","year":"2026"},"n_packages":3,"n_references":2,"next":{"headline":"vLLM before 0.27.0 Denial of Service via DeepStream Backend","id":"CVE-2026-78684"},"packages":[{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":null,"source":"GHSA-rhp5-r9x4-f5g2"},{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"GHSA-rhp5-r9x4-f5g2"},{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"PYSEC-2026-3734"}],"prev":{"headline":"NLTK before 3.10.3 SSRF Protection Bypass via Proxy","id":"CVE-2026-78682"},"products":["nltk"],"published":"2026-08-25","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":9.3,"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":"total"},"state":"PUBLISHED","updated":"2026-08-25","vendors":["nltk"]},"summary":"Attackers can execute arbitrary code by tricking applications into loading malicious model files via unsafe pickle deserialization in NLTK.","url":"https://insights.sbomify.com/CVE-2026-78683/"}