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Fencer Vulns
medium 5.9

CVE-2026-54291 json

Silent channel-binding authentication downgrade via unsupported certificate algorithms

published 2026-07-06 4 mo ago modified 2026-09-10 1 mo ago also BIT-postgresql-jdbc-driver-2026-54291 , EUVD-2026-41903 , GHSA-j92g-9f8w-j867

cvss
5.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.postgresql:postgresql 42.7.12
  • bitnami postgresql-jdbc-driver 42.7.12
  • org.postgresql postgresql 42.7.12
  • postgresql postgresql_jdbc_driver 42.7.12
  • libpgjava Debian 14 42.7.12-1

debian advisories DEBIAN-CVE-2026-54291

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-54291 updated cvss 5.9

org.postgresql/postgresql: com.ongres.scram/scram-client: pgjdbc: Man-in-the-middle protection bypass via SCRAM-SHA-256-PLUS downgrade

  • Red Hat Cryostat 4 postgresql 42.7.7.redhat-00001 Red Hat AMQ Broker 7 postgresql 42.7.7.redhat-00001 Red Hat build of Apicurio Registry 3 postgresql 42.7.7.redhat-00001 Red Hat build of Debezium 3 postgresql 42.7.7.redhat-00001
    affected: no fix planned “Will not fix”
  • Red Hat Build of Keycloak postgresql 42.7.7.redhat-00001
    affected: no fix available
  • Red Hat Data Grid 8 postgresql 42.7.7.redhat-00001
    affected: no fix planned “Will not fix”
  • Red Hat Single Sign-On 7 postgresql 42.7.7.redhat-00001
    affected: no fix available “Fix deferred”
  • Red Hat build of Keycloak 26.4.15
    fixed: vendor fix RHSA-2026:56520
  • Red Hat build of Keycloak 26.6.6
    fixed: vendor fix RHSA-2026:56523
  • Red Hat build of Quarkus 3.27.5
    fixed: vendor fix RHSA-2026:53643
  • Red Hat build of Quarkus 3.33.3
    fixed: vendor fix RHSA-2026:51653
show 1 more
  • Red Hat Hardened Images mariadb10.11 3:10.11.18-1.hum1
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 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
CNA 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/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
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
maven org.postgresql:postgresql
>=42.7.4, <42.7.12
42.7.12
bitnami postgresql-jdbc-driver
>=42.7.4, <42.7.12
42.7.12

Affected products

  • pgjdbc pgjdbc

Classification

Weakness
  • CWE-636 Not Failing Securely
  • CWE-757 Selection of Less-Secure Algorithm During Negotiation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.