{"answers":{"affected":"1 open source package ship an affected version, including devalue.","exploited":"There is no known exploitation of CVE-2026-123567 in the wild and no public exploit code.","exposure":"","fix":"Upgrade devalue to 5.6.4 or later.","what":"CVE-2026-123567 is a medium-severity vulnerability in sveltejs devalue, published on 8 Nov 2026."},"fix_prompt":"Check this codebase for CVE-2026-123567 and fix it if it is affected.\n\nWhat it is: CVE-2026-123567 is a medium-severity vulnerability in sveltejs devalue, published on 8 Nov 2026. \nExploitation: There is no known exploitation of CVE-2026-123567 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- devalue (npm): affected from 4.0.0; fixed in 5.6.4\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-2026-123567/ (Markdown: https://insights.sbomify.com/CVE-2026-123567/index.md)","id":"CVE-2026-123567","markdown":"https://insights.sbomify.com/CVE-2026-123567/index.md","name":"CVE-2026-123567","record":{"aliases":["GHSA-8f8h-hxr2-jrh3","GHSA-mwv9-gp5h-frr4"],"analysis":null,"analysis_generated_by":null,"assigner":"VulnCheck","cpe":[],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-1321","name":"Improperly Controlled Modification of Object Prototype Attributes"}],"description":"Sveltejs devalue before 5.6.4 contains a prototype injection vulnerability that allows attackers to inject __proto__ own properties into objects returned by devalue.parse and devalue.unflatten. Attackers can supply crafted serialized input that, when downstream code merges results via Object.assign, alters the target object's prototype.","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":false,"headline":"Sveltejs devalue before 5.6.4 Prototype Injection via parse and unflatten","id":"CVE-2026-123567","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":1,"n_references":2,"next":{"headline":"Sveltejs devalue before 5.6.3 Prototype Pollution via uneval Output","id":"CVE-2026-123568"},"nickname":null,"packages":[{"ecosystem":"npm","fixed":["5.6.4"],"introduced":["4.0.0"],"last_affected":[],"package":"devalue","purl":null,"source":"GHSA-mwv9-gp5h-frr4"}],"prev":{"headline":"Devalue before 5.9.3 CPU Amplification Denial of Service via uneval","id":"CVE-2026-123566"},"products":["devalue"],"published":"2026-11-08","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-11-08","vendors":["sveltejs"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-123567/"}