Authentication downgrade via empty channel-binding data
Published Jul 6, 2026 · Updated Jul 6, 2026
Authentication downgrade in pgJDBC 42.7.4 through 42.7.11 allows man-in-the-middle attackers to bypass required channel binding. ScramAuthenticator accepts an empty certificate-derived binding value and verifies only that the server advertised a PLUS mechanism, not that negotiation selected one. Exploitation requires channelBinding=require, TLS interception, and a certificate algorithm lacking a tls-server-end-point hash; the resulting connection loses its intended man-in-the-middle protection.
Summary
What happened
Authentication downgrade in pgJDBC 42.7.4 through 42.7.11 allows man-in-the-middle attackers to bypass required channel binding. ScramAuthenticator accepts an empty certificate-derived binding value and verifies only that the server advertised a PLUS mechanism, not that negotiation selected one. Exploitation requires channelBinding=require, TLS interception, and a certificate algorithm lacking a tls-server-end-point hash; the resulting connection loses its intended man-in-the-middle protection.
The record
- CVE
- CVE-2026-54291
- Published
- Jul 6, 2026
- Updated
- Jul 6, 2026
- Vendor
- PostgreSQL Global Development Group
- Product
- PostgreSQL JDBC Driver
- Classifications
- CWE-757, CWE-636, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 6, 2026CVE publishedPublication date reported by the CVE source.
- Jul 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 42.7.4, < 42.7.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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