{"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-2026-81722 exists.","fix":"Upgrade nltk to 3.10.3 or later.","what":"CVE-2026-81722 is a high-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-2026-81722 and fix it if it is affected.\n\nWhat it is: CVE-2026-81722 is a high-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-2026-81722 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-2026-81722/ (Markdown: https://insights.sbomify.com/CVE-2026-81722/index.md)","id":"CVE-2026-81722","markdown":"https://insights.sbomify.com/CVE-2026-81722/index.md","name":"CVE-2026-81722","record":{"aliases":["DEBIAN-CVE-2026-81722","ECHO-4ba5-a214-fe9e","GHSA-ww6m-cw3f-q94g","MINI-q424-r29p-q863","PYSEC-2026-3738","UBUNTU-CVE-2026-81722"],"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":"An attacker can cause a denial of service by submitting a specially crafted token to the PorterStemmer, leading to excessive CPU consumption.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[{"product":"nltk","vendor":"nltk"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-407","name":"Inefficient Algorithmic Complexity"}],"description":"nltk PorterStemmer in versions \u003c= 3.10.2 (fixed in 3.10.3) contains an inefficient-algorithmic-complexity denial of service in PorterStemmer.stem(). The _is_consonant() helper walks backward over the entire run of trailing 'y' characters on every call, and _measure() invokes it for each stem position, causing O(n^2) behavior. A single ~20-50 KB untrusted token consisting of a long run of the letter 'y' followed by a matching suffix (e.g., 'ness') can pin a CPU core for seconds to minutes, causing availability impact.","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 PorterStemmer before 3.10.3 Quadratic-time DoS","id":"CVE-2026-81722","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 Quadratic CPU Exhaustion via XMLCorpusView","id":"CVE-2026-81723"},"packages":[{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":null,"source":"GHSA-ww6m-cw3f-q94g"},{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"GHSA-ww6m-cw3f-q94g"},{"ecosystem":"PyPI","fixed":["3.10.3"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"PYSEC-2026-3738"}],"prev":{"headline":"openssl_encrypt before 1.4.9 Denial of Service via KDF","id":"CVE-2026-81721"},"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"}],"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":"2026-08-27","vendors":["nltk"]},"summary":"An attacker can cause a denial of service by submitting a specially crafted token to the PorterStemmer, leading to excessive CPU consumption.","url":"https://insights.sbomify.com/CVE-2026-81722/"}