CVE-2026-91924

pgweb through 0.17.0 fails to properly guard the POST /api/connect endpoint when the connect-backend authorization mode is configured. An attacker with low-privileged access to a pgweb instance can supply an arbitrary database connection URL along with a custom session identifier, bypassing the configured resource-to-database mapping. This allows the attacker to connect to databases they are not authorized to access and to reach other internal services reachable from the pgweb host, exposing sensitive data from those back-end systems. Deployments affected are self-hosted pgweb instances that enable connect-backend with authorization and are exposed to users or networks the operator does not fully trust. No public proof of concept is known and the flaw is not listed in CISA's KEV catalog.

What to do: Upgrade pgweb to a release newer than 0.17.0 as soon as a fixed version is available. Until then, do not expose pgweb instances using connect-backend mode to untrusted networks or users, and restrict the pgweb host's network egress so it cannot reach internal databases or services it is not intended to front. Review pgweb logs for unexpected POST /api/connect requests with unfamiliar session identifiers or connection URLs, and verify that no unauthorized database or internal service connections occurred.