{"id":"EEF-CVE-2026-77950","summary":"RPC error handler fails open in AshTypescript, disclosing unredacted errors","details":"## Summary\n\nGeneration of Error Message Containing Sensitive Information vulnerability in ash-project ash_typescript allows an unauthenticated attacker to receive unredacted internal error data by provoking an error shape the configured error handler does not match.\n\n`apply_error_handler/3` in `lib/ash_typescript/rpc/errors.ex` is the only hook an application has for redacting or suppressing errors before they reach the client, with a `nil` return dropping the error entirely. Its `rescue` clause logs a warning and then returns the original, pre-handler error map. Error handlers are conventionally written as pattern-matching functions over expected error shapes, so an unmatched shape raises `FunctionClauseError` and the raw transformed error, including any secrets carried in `vars`, is emitted instead. An intent to suppress an error becomes an intent to publish it. The `rescue` catches exceptions only, so a handler that throws or exits still propagates.\n\nThis issue affects ash_typescript: from 0.8.0 before 0.18.0.\n\n## Configurations\n\nThe application exposes an AshTypescript RPC endpoint over HTTP and configures a custom `error_handler` in its `typescript_rpc` domain section for redaction or suppression.","aliases":["CVE-2026-77950","GHSA-mjr7-r3rf-x963"],"modified":"2026-09-08T03:45:05.340741212Z","published":"2026-09-01T02:08:54.754Z","database_specific":{"capec_ids":["CAPEC-54"],"cpe_ids":["cpe:2.3:a:ash-project:ash_typescript:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-209"]},"references":[{"type":"ADVISORY","url":"https://github.com/ash-project/ash_typescript/security/advisories/GHSA-mjr7-r3rf-x963"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-77950.html"},{"type":"FIX","url":"https://github.com/ash-project/ash_typescript/commit/59d8e985a98cf2e01794dbe5b919b897a95311f4"},{"type":"PACKAGE","url":"https://hex.pm/packages/ash_typescript"}],"affected":[{"package":{"name":"ash_typescript","ecosystem":"Hex","purl":"pkg:hex/ash_typescript"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.8.0"},{"fixed":"0.18.0"}]}],"versions":["0.10.0","0.10.1","0.10.2","0.11.0","0.11.1","0.11.2","0.11.3","0.11.4","0.11.5","0.11.6","0.12.0","0.12.1","0.13.0","0.13.1","0.13.2","0.14.0","0.14.1","0.14.2","0.14.3","0.14.4","0.15.0","0.15.1","0.15.2","0.15.3","0.16.0","0.17.0","0.17.1","0.17.2","0.17.3","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.9.0","0.9.1"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-77950.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/ash-project/ash_typescript","events":[{"introduced":"cb01cc8749e5a2a17fb45aedbe75df30a9f1126e"},{"fixed":"59d8e985a98cf2e01794dbe5b919b897a95311f4"}]}],"versions":["v0.15.0","v0.15.3","v0.15.2","v0.15.1","v0.14.4","v0.14.3","v0.14.2","v0.14.1","v0.14.0","v0.13.2","v0.13.1","v0.13.0","v0.12.1","v0.12.0","v0.11.6","v0.11.5","v0.11.4","v0.11.3","v0.11.2","v0.11.1","v0.11.0","v0.10.2","v0.10.1","v0.10.0","v0.9.1","v0.9.0","v0.8.4","v0.8.3","v0.8.2","v0.8.1","v0.8.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-77950.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"}],"credits":[{"name":"Peter Ullrich","type":"FINDER"},{"name":"Peter Ullrich","type":"REPORTER"},{"name":"Torkild Gundersen Kjevik / Ash Project","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"COORDINATOR"}]}