{"id":"GHSA-h9w6-f932-gq62","summary":"ses's global contour bindings leak into Compartment lexical scope","details":"### Impact\n\nWeb pages and web extensions using `ses` and the `Compartment` API to evaluate third-party code in an isolated execution environment that have also elsewhere used `const`, `let`, and `class` bindings in the top-level scope of a `\u003cscript\u003e` tag will have inadvertently revealed these bindings in the lexical scope of third-party code.\n\n### Patches\n\nThis compromise is addressed in `ses` version `1.12.0`. The mechanism for confining third-party code involves a `with` block and a semi-opaque scope `Proxy`. The proxy previously revealed any named property to the surrounding lexical scope if it were absent on `globalThis`, so that the third-party code would receive an informative `ReferenceError`, relying on the invalid assumption that only properties of `globalThis` are in the top-level lexical scope. The solution makes the scope proxy fully opaque. Consequently, accessing an unbound free lexical name will produce `undefined` instead of throwing `ReferenceError`.\nAssigning to an unbound free lexical name will continue to throw a `ReferenceError`.\n\n### Workarounds\n\nThis problem can be mitigated either by avoiding top-level `let`, `const`, or `class` bindings in `\u003cscript\u003e` tags, which is an existing industry best-practice, or change these to `var` bindings to be reflected on `globalThis`, or upgrade `ses` to version `1.12.0` or greater.\n\nSome bundlers by default transform top-level `let`, `const`, and `class` bindings to `var`.\n\n### Disclosure\n\nThis vulnerability was disclosed by @mingijunggrape in the course of their studies at UNIST (Ulsan National Institute of Science and Technology) as a member of the Web Security Lab (https://websec-lab.github.io/).","aliases":["CVE-2025-32792"],"modified":"2025-04-18T18:34:51Z","published":"2025-04-18T15:10:05Z","database_specific":{"github_reviewed_at":"2025-04-18T15:10:05Z","nvd_published_at":"2025-04-18T16:15:23Z","cwe_ids":["CWE-497"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/endojs/endo/security/advisories/GHSA-h9w6-f932-gq62"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-32792"},{"type":"PACKAGE","url":"https://github.com/endojs/endo"}],"affected":[{"package":{"name":"ses","ecosystem":"npm","purl":"pkg:npm/ses"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.12.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/04/GHSA-h9w6-f932-gq62/GHSA-h9w6-f932-gq62.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"}]}