{"id":"CVE-2026-89186","published":"2026-09-16T09:17:07.527","lastModified":"2026-09-16T20:38:33.883","description":"Use of Cache Containing Sensitive Information in ZenHive mpp allows a shared HTTP cache to store a paid response and serve it to clients that never paid.\n\nMPP.Plug.verify_credential in lib/mpp/plug.ex sets payment-receipt and cache-control: private on the connection before the wrapped application runs, and registers no register_before_send/2 callback. Plug.Conn.put_resp_header/3 replaces an existing header, so a mounting application that sets its own cache-control on the paid resource (for example public, max-age=3600) silently overrides the private the library relies on, and a CDN or reverse proxy can then store the paid 200 together with its Payment-Receipt and serve both to unpaid clients. The library-level guarantee is therefore defeatable by the application it protects. For the same reason a downstream non-2xx response still carried Payment-Receipt, issuing a receipt for a response that delivered no resource.\n\nThis issue affects mpp: from 0.1.0 before 0.16.2.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-524"],"vendors":[],"products":[],"references":[{"url":"https://cna.erlef.org/cves/CVE-2026-89186.html","tags":[]},{"url":"https://github.com/ZenHive/mpp/commit/2d4d1d94aae7790ae0623063961adbeef171fa71","tags":[]},{"url":"https://github.com/ZenHive/mpp/commit/2fd91a5ecbd0b0ad2a4ac202b79659e8126dbc0b","tags":[]},{"url":"https://github.com/ZenHive/mpp/security/advisories/GHSA-82qh-vrvm-gqvc","tags":[]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-89186","tags":[]}],"exploitRefs":[{"url":"https://github.com/ZenHive/mpp/commit/2d4d1d94aae7790ae0623063961adbeef171fa71","tags":[]},{"url":"https://github.com/ZenHive/mpp/commit/2fd91a5ecbd0b0ad2a4ac202b79659e8126dbc0b","tags":[]},{"url":"https://github.com/ZenHive/mpp/security/advisories/GHSA-82qh-vrvm-gqvc","tags":[]}],"hasPoc":true,"ai":null}