{"answers":{"affected":"2 open source packages ship an affected version, including @toon-format/toon.","exploited":"There is no known exploitation of CVE-2026-82404 in the wild and no public exploit code.","fix":"Upgrade @toon-format/toon to 2.3.1 or later.","what":"CVE-2026-82404 is a high-severity unsafe deserialization vulnerability in toon-format toon, published on 2 Sep 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-2026-82404 and fix it if it is affected.\n\nWhat it is: CVE-2026-82404 is a high-severity unsafe deserialization vulnerability in toon-format toon, published on 2 Sep 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-2026-82404 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- @toon-format/toon (npm): affected all versions; fixed in 2.3.1\n- @toon-format/toon (npm): affected all versions; fixed in 2.3.1\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-2026-82404/ (Markdown: https://insights.sbomify.com/CVE-2026-82404/index.md)","id":"CVE-2026-82404","markdown":"https://insights.sbomify.com/CVE-2026-82404/index.md","name":"CVE-2026-82404","record":{"aliases":["GHSA-p95v-992w-h6c3"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"TOON serialization library","requires_auth":"none","summary":"Attackers can achieve remote code execution or denial of service by sending crafted TOON input that pollutes the object prototype.","user_interaction":"not_required","vuln_class":"deserialization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":8.3,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L","version":"3.1"},"cwes":[{"id":"CWE-1321","name":"Improperly Controlled Modification of Object Prototype Attributes"}],"description":"TOON is a compact, human-readable serialization of JSON data for LLM prompts. Prior to 2.3.1, decoding attacker-controlled TOON with a __proto__, constructor, or prototype key wrote through the object prototype chain instead of creating an own property, polluting Object.prototype for the runtime. In packages/toon/src/decode/expand.ts, the expandPaths: 'safe' path and insertPathSafe function made dotted keys such as a.__proto__.x the strongest vector, while plain nested objects, tabular rows, quoted keys, and streaming decode were also affected. The encoder also dropped own __proto__ properties and could invoke an inherited setter during normalization. Services that decode untrusted TOON could experience denial of service or, when a suitable downstream gadget is present, remote code execution. This issue is fixed in version 2.3.1.","ecosystems":["npm"],"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":"TOON: Prototype pollution when decoding untrusted TOON input","id":"CVE-2026-82404","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":"deserialization","year":"2026"},"n_packages":2,"n_references":4,"next":{"headline":"Klever-Go Account takeover: `kleverUpdateAccountPermission` authorizes on attacker-controlled `RecipientAddr` instead of the authenticated caller","id":"CVE-2026-82405"},"packages":[{"ecosystem":"npm","fixed":["2.3.1"],"introduced":["0"],"last_affected":[],"package":"@toon-format/toon","purl":null,"source":"GHSA-p95v-992w-h6c3"},{"ecosystem":"npm","fixed":["2.3.1"],"introduced":["0"],"last_affected":[],"package":"@toon-format/toon","purl":"pkg:npm/%40toon-format/toon","source":"GHSA-p95v-992w-h6c3"}],"prev":{"headline":"Gogs: Open Redirect in /redirect endpoint via backslash bypass in `IsSameSite`","id":"CVE-2026-82402"},"products":["toon"],"published":"2026-09-02","related":[],"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":"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":"2026-09-02","vendors":["toon-format"]},"summary":"Attackers can achieve remote code execution or denial of service by sending crafted TOON input that pollutes the object prototype.","url":"https://insights.sbomify.com/CVE-2026-82404/"}