{"answers":{"affected":"3 open source packages ship an affected version, including nltk. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-63311 in the wild and no public exploit code.","fix":"Upgrade nltk to 3.10.0 or later.","what":"CVE-2026-63311 is a medium-severity server-side request forgery vulnerability in nltk, published on 22 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-2026-63311 and fix it if it is affected.\n\nWhat it is: CVE-2026-63311 is a medium-severity server-side request forgery vulnerability in nltk, published on 22 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-63311 in the wild and no public exploit code.\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-2026-63311/ (Markdown: https://insights.sbomify.com/CVE-2026-63311/index.md)","id":"CVE-2026-63311","markdown":"https://insights.sbomify.com/CVE-2026-63311/index.md","name":"CVE-2026-63311","record":{"aliases":["DEBIAN-CVE-2026-63311","ECHO-2c96-e20c-40c3","GHSA-3gqm-fcw5-w839","MINI-98jg-5c66-g23m","PYSEC-2026-3723","UBUNTU-CVE-2026-63311"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Python NLP library","requires_auth":"none","summary":"Attackers can bypass SSRF protections in NLTK via DNS failures to access restricted network resources, including cloud metadata endpoints.","user_interaction":"not_required","vuln_class":"ssrf"},"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:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L","version":"4.0"},"cwes":[{"id":"CWE-918","name":"Server-Side Request Forgery"}],"description":"NLTK before 3.10.0 (affected versions \u003c= 3.9.4) contains a server-side request forgery (SSRF) vulnerability in the validate_network_url() function in nltk/pathsec.py. The _resolve_hostname() helper catches OSError and ValueError during socket.getaddrinfo() and returns an empty list; when DNS resolution fails, the validation loop executes no IP checks and the function fails open, allowing urlopen() to proceed without validation. An attacker who can trigger DNS resolution failures or use DNS rebinding can bypass SSRF protections and reach restricted network resources, including cloud metadata endpoints (e.g., 169.254.169.254).","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"NLTK before 3.10.0 SSRF via DNS Resolution Failure","id":"CVE-2026-63311","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"ssrf","year":"2026"},"n_packages":3,"n_references":2,"next":{"headline":"NLTK StreamBackedCorpusView Bypasses pathsec.ENFORCE Arbitrary File Read","id":"CVE-2026-63312"},"packages":[{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":null,"source":"GHSA-3gqm-fcw5-w839"},{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"GHSA-3gqm-fcw5-w839"},{"ecosystem":"PyPI","fixed":["3.10.0"],"introduced":["0"],"last_affected":[],"package":"nltk","purl":"pkg:pypi/nltk","source":"PYSEC-2026-3723"}],"prev":{"headline":"This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.","id":"CVE-2026-63310"},"products":["nltk"],"published":"2026-08-22","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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-26","vendors":["nltk"]},"summary":"Attackers can bypass SSRF protections in NLTK via DNS failures to access restricted network resources, including cloud metadata endpoints.","url":"https://insights.sbomify.com/CVE-2026-63311/"}