Stored cross-site scripting in pgAdmin 4's error-rendering and plan-node-rendering paths. Text returned by a PostgreSQL server (ErrorResponse messages, including object names quoted back inside relation-does-not-exist errors and inside EXPLAIN Recheck Cond / Exact Heap Blocks fields) was passed verbatim through html-react-parser at every user-facing sink — the notifier toasts, FormFooterMessage / FormInput help and error areas, FormNote, ModalProvider AlertContent and confirmDelete, ToolErrorView, the Explain visualiser's NodeText panel, the SQL editor confirm dialogs, ConfirmSaveContent, PreferencesHelper modal alerts, and SelectThemes helper text. A PostgreSQL server an attacker controls — or any server returning attacker-influenced text such as a table or column name a low-privilege database user can create — could inject arbitrary HTML (including <iframe>) into the pgAdmin DOM the moment the victim's pgAdmin connected to that server or viewed an Explain plan that referenced the crafted object.

The injected iframe's srcdoc could fetch attacker-served JavaScript and, by writing to parent.location, redirect the victim's top-level pgAdmin browser tab to an attacker-controlled URL. Because the injection originates from inside pgAdmin's own interface, standard anti-clickjacking controls (X-Frame-Options, Content-Security-Policy: frame-ancestors) do not mitigate it. A phishing page rendered inside the legitimate pgAdmin window is indistinguishable from a genuine pgAdmin dialog.

Fix combines three complementary layers. (1) DOMPurify sanitisation is wrapped around every html-react-parser call site reachable from notifier, alert, form-error, Explain, and SQL-editor flows. (2) A new plain-text rendering contract — SafeMessage / SafeHtmlMessage components plus Notifier.errorText / alertText / warningText / infoText / successText helpers — is introduced; around fifty callers across browser, tools, dashboard, debugger, misc, llm, preferences, schema diff, and the SQL editor that previously interpolated backend-derived strings are migrated to the plain-text variants. (3) Backend HTML-escape is applied at the post-connection-SQL handler (execute_post_connection_sql) via a new sanitize_external_text helper, so third-party JSON consumers (audit logs, API clients) never receive raw markup either; the Explain plan-info renderer is also patched to _.escape Recheck Cond and Exact Heap Blocks at construction (matching every sibling field), giving defence in depth even before DOMPurify runs.

This issue affects pgAdmin 4: from 6.0 before 9.16.

AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

CWE-79

CWE-116

https://github.com/pgadmin-org/pgadmin4/commit/9e370d3cb67b83b3945f82969c959fad3f926517

https://github.com/pgadmin-org/pgadmin4/issues/10068

[{"vendor":"pgadmin.org","product":"pgAdmin 4","defaultStatus":"unaffected","modules":["Notifier","Form Components","Modal Provider","Explain Visualiser","Driver"],"programFiles":["https://github.com/pgadmin-org/pgadmin4/blob/master/web/pgadmin/static/js/components/FormComponents.jsx","https://github.com/pgadmin-org/pgadmin4/blob/master/web/pgadmin/static/js/Notifier.jsx","https://github.com/pgadmin-org/pgadmin4/blob/master/web/pgadmin/utils/driver/psycopg3/connection.py","https://github.com/pgadmin-org/pgadmin4/blob/master/web/pgadmin/tools/erd/static/js/erd_tool/components/Explain/Analysis.jsx"],"repo":"https://github.com/pgadmin-org/pgadmin4","versions":[{"version":"6.0","lessThan":"9.16","versionType":"custom","status":"affected"}]}]