CVE-2026-12047: pgAdmin 4: HTML injection in cloud verify_credentials / deploy endpoints via unsanitised SDK exception text
HTML injection in pgAdmin 4's cloud deployment module. The verifycredentials, deploy, regions, and update-server endpoints under /rds/, /azure/, /google/, and the top-level /cloud/ blueprint propagated AWS / Azure / Google SDK exception text — and the related file-resolution and database-commit exception text — into the JSON response body (the info and errormsg fields) without HTML-encoding. The Cloud Wizard frontend rendered these strings through html-react-parser, so an attacker-influenced exception message embedded structural HTML directly into the wizard's DOM.
The reported entry point is /rds/verifycredentials/. An authenticated pgAdmin user submits a crafted accesskey whose value contains an <iframe/src=...> payload; AWS STS rejects the credential with an IncompleteSignature exception whose text quotes the accesskey verbatim; the pgAdmin backend forwards that text into the JSON info field; the Cloud Wizard's FormFooterMessage parses it as HTML. The browser fetches the iframe's src from an attacker-controlled host, and JavaScript executing inside the cross-origin iframe writes to parent.location, redirecting the victim's pgAdmin tab. Because the injection renders inside pgAdmin's own interface, X-Frame-Options and Content-Security-Policy frame-ancestors do not mitigate it. Baseline impact is self-targeted (the same user who supplied the payload sees the injection); escalation against other authenticated users requires an additional cross-site request-forgery primitive capable of submitting the malformed credential request with a valid X-pgA-CSRFToken in the victim's browser context.
The same unsanitised-error-into-JSON pattern was present across multiple sibling endpoints — Azure's checkclusternameavailability, every Google endpoint that surfaces SDK errors (verificationack, projects, regions, instancetypes, databaseversions, the verifycredentials path-resolution branches), the central /deploy endpoint that bubbles str(e) from deployonrds / deployonazure / deployongoogle, and updatecloudserver which surfaces the str(e) from a failing db.session.commit — all of which are now covered.
Fix HTML-escapes every external/SDK exception string at the endpoint sink via a new shared sanitizeexternaltext helper (HTML escape with control-character strip), promoted out of the psycopg3 driver into web/pgadmin/utils/textsanitize.py. The Cloud Wizard frontend additionally renders its FormFooterMessage in plain-text mode for backend-derived strings, so the value is never parsed as HTML even if a future sink forgets the escape.
This issue affects pgAdmin 4: from 6.6 before 9.16.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
pgAdmin 4to a version that resolves this vulnerability.Fixed in 9.16 - Configuration
Ensure Cloud Wizard FormFooterMessage renders backend-derived strings in plain-text mode (not parsed as HTML), so future sinks cannot reintroduce HTML parsing even if escape is missed.
Cloud Wizard frontend (FormFooterMessage) render_mode = plain-text - Configuration
Do not render backend-derived error/exception strings through html-react-parser; treat exception-derived fields as text so attacker-controlled exception content cannot embed structural HTML in the wizard DOM.
Cloud Wizard frontend (FormFooterMessage rendering pipeline) html-react-parser usage = disabled_for_backend_derived_exception_strings - Configuration
At the endpoint sink, HTML-escape every external/SDK exception string by using the new shared sanitize_external_text helper (HTML escape + control-character strip). Promote it into web/pgadmin/utils/text_sanitize.py and apply it to JSON fields that currently bubble SDK/exception text such as info/errormsg (including /rds/verify_credentials/ entry point and related /rds/, /azure/, /google/, and /cloud/ flows mentioned).
pgAdmin backend endpoint sink (Cloud deployment module) sanitize_external_text helper = HTML escape with control-character strip
Event History
Frequently Asked Questions
What is the severity of CVE-2026-12047?
The severity of CVE-2026-12047 is rated as low with a score of 3.5.
How do I fix CVE-2026-12047?
To fix CVE-2026-12047, ensure to sanitize SDK exception text in the cloud deployment module endpoints.
What impact does CVE-2026-12047 have on pgAdmin 4?
CVE-2026-12047 allows for HTML injection which could affect the integrity of web interfaces in pgAdmin 4.
Which components of pgAdmin 4 are affected by CVE-2026-12047?
The cloud verify_credentials, deploy, regions, and update-server endpoints under /rds/, /azure/, /google/, and /cloud/ are affected by CVE-2026-12047.
What type of vulnerability is CVE-2026-12047?
CVE-2026-12047 falls under the categories of XSS and CSRF vulnerabilities.