{"answers":{"affected":"1 open source package ship an affected version, including livebook. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-66881 exists.","fix":"Upgrade livebook to a fixed version for your release line: 0.18.7 or 0.19.9.","what":"CVE-2026-66881 is a high-severity path traversal vulnerability in livebook-dev livebook, published on 5 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-2026-66881 and fix it if it is affected.\n\nWhat it is: CVE-2026-66881 is a high-severity path traversal vulnerability in livebook-dev livebook, published on 5 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-2026-66881 exists.\n\nAffected packages and fixed versions:\n- livebook (Hex): affected from 0.11.0; fixed in 0.18.7, 0.19.9\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-2026-66881/ (Markdown: https://insights.sbomify.com/CVE-2026-66881/index.md)","id":"CVE-2026-66881","markdown":"https://insights.sbomify.com/CVE-2026-66881/index.md","name":"CVE-2026-66881","record":{"aliases":["EEF-CVE-2026-66881","GHSA-r4h8-2xpq-v48g"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["code_execution","data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"Livebook notebook server","requires_auth":"none","summary":"Attacker-authored notebooks can write arbitrary files to the server via path traversal in imported file entries, potentially leading to code execution.","user_interaction":"required","vuln_class":"path_traversal"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[{"product":"livebook","vendor":"livebook"}],"cvss":{"score":7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-23","name":"Relative Path Traversal"}],"description":"Relative Path Traversal vulnerability in livebook-dev livebook allows an attacker-authored notebook to write a file with attacker-controlled content to an arbitrary path.\n\nA .livemd notebook can declare file_entries metadata, each entry carrying a name. Every path that creates a file entry through the user interface validates that name with Livebook.Notebook.validate_file_entry_name/2, which requires a flat filename of alphanumerics, dashes, underscores and dots, ending in an extension. The import path does not: Livebook.LiveMarkdown.Import.file_entry_metadata_to_attrs/1 in lib/livebook/live_markdown/import.ex takes the name verbatim from the notebook source.\n\nFor a URL-type file entry, Livebook.Session.file_entry_cache_file/2 in lib/livebook/session.ex resolves that name beneath the session's temporary directory without checking that the result stays inside it, and Livebook.FileSystem.Utils.resolve_unix_like_path/2 collapses parent-directory segments while clamping only at the filesystem root. When the entry's content is requested and no cached copy exists, Livebook fetches the entry's URL and writes the response body to the resolved path, creating parent directories as needed. The attacker therefore controls both the destination and the contents of the written file, which may land anywhere the Livebook process can write. The same missing containment check is present in Livebook.Session.to_attachment_file_entry/2.\n\nA victim who opens an attacker-supplied notebook and causes the entry to be fetched triggers the write within their own authenticated session; the attacker needs no account on the target instance. URL-type entries are also not placed under notebook stamping quarantine on import, so no warning is shown.\n\nThis issue affects livebook: from 0.11.0 before 0.18.7 and from 0.19.0 before 0.19.9.","ecosystems":["Hex"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"Path traversal in imported file_entries name allows arbitrary file write via URL-type entry download","id":"CVE-2026-66881","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"path_traversal","year":"2026"},"n_packages":1,"n_references":6,"next":{"headline":"Reflected XSS in AshAuthentication confirmation and magic link interaction forms","id":"CVE-2026-66882"},"packages":[{"ecosystem":"Hex","fixed":["0.18.7","0.19.9"],"introduced":["0.11.0","0.19.0"],"last_affected":[],"package":"livebook","purl":"pkg:hex/livebook","source":"EEF-CVE-2026-66881"}],"prev":{"headline":"Information disclosure in Red Hat Advanced Cluster Management for Kubernetes 2.11","id":"CVE-2026-66878"},"products":["livebook"],"published":"2026-08-05","related":[{"cvss_score":8.6,"headline":"JS-view sandboxed output can synthesize keyboard events to trigger unconfirmed global shortcuts","id":"CVE-2026-66298","kev_date_added":null,"published":"2026-08-05"},{"cvss_score":8.6,"headline":"Livebook Desktop's protocol handler can be exploited to execute arbitrary command on Windows","id":"CVE-2023-35174","kev_date_added":null,"published":"2023-06-22"},{"cvss_score":7.7,"headline":"Livebook Teams identity check fails open when the deployment group is unresolvable, allowing unauthenticated access","id":"CVE-2026-68746","kev_date_added":null,"published":"2026-08-05"},{"cvss_score":6.8,"headline":"Livebook Teams identity callback lacks state binding, allowing login CSRF","id":"CVE-2026-66885","kev_date_added":null,"published":"2026-08-05"},{"cvss_score":5,"headline":"Unescaped deployment environment variables in generated setup commands","id":"CVE-2026-66297","kev_date_added":null,"published":"2026-08-05"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Erlang Ecosystem Foundation","prefix":"EEF"},{"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":"2026-08-06","vendors":["livebook-dev"]},"summary":"Attacker-authored notebooks can write arbitrary files to the server via path traversal in imported file entries, potentially leading to code execution.","url":"https://insights.sbomify.com/CVE-2026-66881/"}