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CVE-2026-54291 pgjdbc CVE debrief

The CVE-2026-54291 vulnerability in pgjdbc, a PostgreSQL JDBC driver, allows for a silent downgrade of SCRAM-SHA-256-PLUS with channel binding to plain SCRAM-SHA-256 without it. This downgrade can be triggered by an attacker who can intercept the TLS connection with a certificate whose signature algorithm has no tls-server-end-point channel-binding hash. The issue arises 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 vulnerability is fixed in version 42.7.12.

Vendor
pgjdbc
Product
Unknown
CVSS
HIGH 8.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-06
Original CVE updated
2026-07-09
Advisory published
2026-07-06
Advisory updated
2026-07-09

Who should care

Users of PostgreSQL JDBC driver versions 42.7.4 through 42.7.11 who rely on SCRAM-SHA-256-PLUS for authentication should be concerned about this vulnerability. An attacker could exploit this to intercept and manipulate data, potentially leading to unauthorized access or data breaches.

Technical summary

The pgjdbc vulnerability CVE-2026-54291 allows for a silent downgrade of the SCRAM-SHA-256-PLUS authentication mechanism to SCRAM-SHA-256, which lacks channel binding. This occurs because the com.ongres.scram:scram-client library returns an empty byte array instead of failing when encountering a server certificate with no tls-server-end-point channel-binding hash. As a result, an attacker can intercept the TLS connection and trigger the downgrade, bypassing the man-in-the-middle protection that SCRAM-SHA-256-PLUS is designed to provide. The vulnerability is addressed in pgjdbc version 42.7.12.

Defensive priority

High

Recommended defensive actions

  • Upgrade to pgjdbc version 42.7.12 or later
  • Use SCRAM-SHA-256-PLUS with channel binding for authentication
  • Monitor for and block suspicious downgrade attempts
  • Implement additional security measures such as TLS inspection and filtering
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE-2026-54291 vulnerability was publicly disclosed on 2026-07-06T19:17:08.407Z and last modified on 2026-07-09T13:16:25.717Z. The NVD entry is currently Analyzed. The vulnerability affects PostgreSQL JDBC driver versions 42.7.4 through 42.7.11.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-54291 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-54291

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-54291 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-54291

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.