CVE-2026-54291 Silent channel-binding authentication downgrade via unsupported certificate algorithms
Attackers can bypass channel-binding protections in PostgreSQL JDBC connections by triggering a silent authentication downgrade, enabling man-in-the-middle attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54291?
CVE-2026-54291 is a high-severity vulnerability in pgjdbc, published on 6 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-54291?
3 open source packages ship an affected version, including org.postgresql:postgresql and postgresql-jdbc-driver. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.postgresql:postgresql Maven | From 42.7.4 | 42.7.12 |
org.postgresql:postgresql Maven | From 42.7.4 | 42.7.12 |
postgresql-jdbc-driver Bitnami | From 42.7.4 | 42.7.12 |
Products include Postgresql Postgresql Jdbc Driver.
How do I fix CVE-2026-54291?
Upgrade org.postgresql:postgresql to 42.7.12 or later.
Is CVE-2026-54291 being exploited?
There is no known exploitation of CVE-2026-54291 in the wild and no public exploit code.
Other vulnerabilities in pgjdbc
- CVE-2025-49146 pgjdbc Client Allows Fallback to Insecure Authentication Despite channelBinding=require Configuration
- CVE-2018-10936 Moderate severity vulnerability that affects org.postgresql:pgjdbc-aggregate
- CVE-2026-42198 pgjdbc: Unbounded PBKDF2 iterations in SCRAM authentication allows CPU exhaustion DoS
Sources
Also known as BIT-postgresql-jdbc-driver-2026-54291, CLEANSTART-2026-EP87494, CLEANSTART-2026-KV94279, CLEANSTART-2026-WV63281, CLEANSTART-2026-XF69190, CLEANSTART-2026-ZS37563 and 26 more.