HighCVE-2026-54291

    Silent channel-binding authentication downgrade via unsupported certificate algorithms (CVE-2026-54291)

    Published Last modified Sources: BSI, Red Hat, OSV, CVE.org

    What is affected, what to do

    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.

    Update postgresql_jdbc_driver to version 42.7.12, PostgreSQL JDBC Driver to version 42.7.12, JobScheduler to version 2.8.5.

    Affected
    • Pgjdbc gte 42.7.4, < 42.7.12..*

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    Metrics

    8.2

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v4

    5.9

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: BSI, Red Hat, OSV, CVE.org

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 13.7

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    63.24 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    8.2 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.9
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.2
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.2 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    13.7
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-636, CWE-757

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: BSI WID Portal, BSI CSAF, redhat_csaf, OSV (Open Source Vulnerabilities), cvelistv5, NVD (NIST), CVE.org (MITRE)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    VendorProductAffected versionsFixed in
    pgjdbcpgjdbc
    • ≥ 42.7.4, < 42.7.12
    • —
    postgresqlpostgresql_jdbc_driver
    • 42.7.4 – < 42.7.12
    • 42.7.12
    Open SourcePostgreSQL JDBC Driver
    • < 42.7.12
    • 42.7.12
    OracleCommunications
    • 7.5.0
    • 15.0.1.0.0
    • 26.1.202
    • 7.7.0
    • 25.1.100
    • 47.0.0.2.0
    • 7.0.0
    • 6
    • 6.1
    • 7.8.0
    • 24.2.4-25.2.000
    • 7.5.1
    • 25.2.100
    • 8.0-8.1
    • 8.0.1
    • 7.6.0
    • 14
    • 15.1.0.0.0
    • 25.1.200
    • 6.1.1-7.0.0
    • 25.2.200
    • 15.2.0.0.0
    • 11
    • 26.1.200
    • 25.2.202
    • 25.2.201
    • 15.0.0.0.0
    • 8.0-8.3
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    SOS GmbHJobScheduler
    • < 2.8.5
    • 2.8.5

    Weakness classes (CWE)

    • CWE-636Not Failing Securely ('Failing Open')

      Class

      When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.

      Entry at MITRE CWE-636

    • CWE-757Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')

      Base

      A protocol or its implementation supports interaction between multiple actors and allows those actors to negotiate which algorithm should be used as a protection mechanism such as encryption or authentication, but it does not select the strongest algorithm that is available to both parties.

      Entry at MITRE CWE-757

    References & sources

    • github.comongres/scram/releases/tag/3.3web, x_refsource_MISC
    • github.compgjdbc/pgjdbc/commit/77df98e4e66c12936ded3478a0954f6f580bad99web, x_refsource_MISC
    • github.compgjdbc/pgjdbc/security/advisories/GHSA-j92g-9f8w-j867web, x_refsource_CONFIRM
    • NVD (NIST)vuln/detail/CVE-2026-54291web
    • github.compgjdbc/pgjdbcpackage

    Reanalysis & status changes

    Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

    1. Initial Analysisnvd@nist.gov

      • CVSS V3.1: after AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
      • CPE Configuration: after OR *cpe:2.3:a:postgresql:postgresql_jdbc_driver:*:*:*:*:*:*:*:* versions from (including) 42.7.4 up to (excluding) 42.7.12
      • Reference Type: after GitHub, Inc.: https://github.com/ongres/scram/releases/tag/3.3 Types: Not Applicable
      • Reference Type: after GitHub, Inc.: https://github.com/pgjdbc/pgjdbc/commit/77df98e4e66c12936ded3478a0954f6f580bad99 Types: Patch

    2. New CVE Receivedsecurity-advisories@github.com

      • Affected: after pgjdbc
      • Description: after 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.
      • CVSS V4.0: after AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      • CWE: after CWE-636
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