Withdrawn by the publisher.

Affected: CleanStart: keycloak

Package keycloak version 26.5.7-r5 fixes 11 vulnerabilities: CVE-2026-54291, CVE-2026-54512, CVE-2026-54513, CVE-2026-54514, CVE-2026-54515...

pgjdbc is an open source postgresql JDBC Driver. In releases 42.7.4 through 42.7.11, channelBinding=require connections can be silently downgraded from SCRAM-SHA-256-PLUS with channel binding to plain SCRAM-SHA-256 without it, losing the man-in-the-middle protection the setting is meant to guarantee. An attacker who can intercept the TLS connection can trigger the downgrade with a certificate whose signature algorithm has no tls-server-end-point channel-binding hash, because the bundled com.ongres.scram:scram-client returns an empty byte array instead of failing and pgJDBC ScramAuthenticator checks only that the server advertised a PLUS mechanism, without rejecting the empty binding or checking that the negotiated mechanism uses channel binding. This issue is fixed in version 42.7.12.

Affected: Maven: org.postgresql:postgresql

### Impact

`channelBinding=require` connections can be silently downgraded from `SCRAM-SHA-256-PLUS` (with channel binding) to plain `SCRAM-SHA-256` (without it), losing the man-in-the-middle protection the setting is meant to guarantee. An attacker who can intercept the TLS connection triggers the downgrade with a certificate whose signature algorithm has no `tls-server-end-point` channel-binding hash. Examples are `Ed25519`, `Ed448`, and post-quantum algorithms.

Two issues combine in releases 42.7.4 through 42.7.11:

1. The bundled `com.ongres.scram:scram-client` (3.1 or 3.2) returns an empty byte array instead of failing when it cannot derive the binding hash for such a certificate. This is the library issue tracked as [GHSA-p9jg-fcr6-3mhf](https://github.com/ongres/scram/security/advisories/GHSA-p9jg-fcr6-3mhf). 2. pgJDBC does not enforce `channelBinding=require` where it matters. `ScramAuthenticator` checks only that the server *advertised* a `-PLUS` mechanism; it neither rejects the empty binding nor checks that the *negotiated* mechanism uses channel binding. The connection therefore downgrades silently, and would do so even against a fixed `scram-client`, because the missing enforcement is in pgJDBC's own code.

Only connections that set `channelBinding=require` are affected. Under the default `prefer` policy, and under `allow` or `disable`, falling back to plain SCRAM is the documented behaviour. Releases before 42.7.4 are unaffected, because they do not support c…

jansi: org.fusesource.jansi/jansi: Jansi: Heap buffer overflow leads to Denial of Service com.ongres.scram/scram-client: com.ongres.scram/scram-common: SCRAM Libraries: Authentication downgrade via TLS man-in-the-middle attack org.postgresql/postgresql: com.ongres.scram/scram-client: pgjdbc: Man-in-the-middle protection bypass via SCRAM-SHA-256-PLUS downgrade org.apache.sshd/sshd-core: Apache MINA SSHD: Unauthorized command execution due to improper certificate validation com.fasterxml.jackson.core/jackson-core: tools.jackson.core/jackson-core: jackson-core: Denial of Service via incomplete fix in async JSON parser

Affected: Ubuntu:14.04:LTS: libpgjava, Ubuntu:16.04:LTS: libpgjava, Ubuntu:Pro:18.04:LTS: libpgjava, Ubuntu:Pro:20.04:LTS: libpgjava, Ubuntu:22.04:LTS: libpgjava, Ubuntu:24.04:LTS: libpgjava, Ubuntu:25.10: libpgjava, Ubuntu:26.04:LTS: libpgjava

pgjdbc is an open source postgresql JDBC Driver. In releases 42.7.4 through 42.7.11, channelBinding=require connections can be silently downgraded from SCRAM-SHA-256-PLUS with channel binding to plain SCRAM-SHA-256 without it, losing the man-in-the-middle protection the setting is meant to guarantee. An attacker who can intercept the TLS connection can trigger the downgrade with a certificate whose signature algorithm has no tls-server-end-point channel-binding hash, because the bundled com.ongres.scram:scram-client returns an empty byte array instead of failing and pgJDBC ScramAuthenticator checks only that the server advertised a PLUS mechanism, without rejecting the empty binding or checking that the negotiated mechanism uses channel binding. This issue is fixed in version 42.7.12.

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in PostgreSQL JDBC Driver ausnutzen, um Sicherheitsvorkehrungen zu umgehen.