PostgreSQL JDBC Driver: Silent channel-binding authentication downgrade via unsupported certificate algorithms

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.2 · CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N · score source

EPSS

• CVE-2026-54291: 0.24% estimated exploitation activity in the next 30 days; percentile 14.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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. 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…

Published by the source

21 Jul 2026, 17:47 UTC

Last modified by the source

21 Jul 2026, 17:47 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j92g-9f8w-j867

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# Patch Next advisory brief: CVE-2026-54291

Advisory: PostgreSQL JDBC Driver: Silent channel-binding authentication downgrade via unsupported certificate algorithms
IDs: CVE-2026-54291, GHSA-j92g-9f8w-j867
Record: https://patchnext.com/advisories/cve-2026-54291 (revision 1, source checked 26 Oct 2026, 16:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.postgresql:postgresql 42.7.12. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.postgresql:postgresql: affected >= 42.7.4, < 42.7.12; fixed in 42.7.12

## Suggested inspection (read-only)
- Maven org.postgresql:postgresql: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.postgresql:postgresql.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j92g-9f8w-j867 (GitHub-reviewed advisory GHSA-j92g-9f8w-j867 lists affected ranges: Maven org.postgresql:postgresql >=42.7.4 <42.7.12)

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