How severe is CVE-2026-54291?

No CVSS score has been assigned to CVE-2026-54291 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-54291?

CVE-2026-54291 affects the following packages: org.postgresql:postgresql (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-54291?

Update org.postgresql:postgresql to 42.7.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54291 is resolved across your whole dependency graph.

How do I detect CVE-2026-54291 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.postgresql:postgresql, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-54291 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-54291 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-54291 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-54291?

CVE-2026-54291 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 14th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-54291?

CVE-2026-54291 is classified as CWE-636 (CWE-636), CWE-757 (CWE-757). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-54291 published, and has it been updated?

CVE-2026-54291 was published on July 6, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2026-54291 — postgresql

Fix: pgjdbc/pgjdbc@77df98e

CVE-2026-54291 is a CWE-636 vulnerability in org.postgresql:postgresql. A fix is available for org.postgresql:postgresql — see the affected versions and patch details below.

Silent channel-binding authentication downgrade via unsupported certificate algorithms

Also known asBIT-postgresql-jdbc-driver-2026-54291GHSA-j92g-9f8w-j867

Published

Jul 6, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-54291.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs14th percentile — riskier than 14% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

☕org.postgresql:postgresql

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

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:

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.
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 therefore downgrades silently, and would do so even against a fixed scram-client, because the missing enforcement is in pgJDBC's own code.

Only connections that set channelBinding=require are affected. Under the default prefer policy, and under allow or disable, falling back to plain SCRAM is the documented behaviour. Releases before 42.7.4 are unaffected, because they do not support channel binding.

Patches

Fixed in pgJDBC 42.7.12. pgJDBC now enforces channel binding in its own code, independently of the scram-client version:

Under channelBinding=require, it fails the connection when no channel-binding data can be extracted from the server certificate, instead of passing an empty value to the SCRAM client. The error names the certificate signature algorithm.
After negotiation, it requires the selected mechanism to use channel binding (a -PLUS mechanism) whenever channelBinding=require is set, regardless of how negotiation resolved.

Upgrade to 42.7.12 or later.

Workarounds

No pgJDBC setting restores channel-binding enforcement on an affected release; upgrading is the fix.

If you cannot upgrade immediately, verify the server certificate at the TLS layer so that a man-in-the-middle cannot present a substitute certificate. Set sslmode=verify-full with a truststore that contains only your server's CA. This defence is independent of channel binding and blocks the same attacker. Connections that rely on channelBinding=require in place of certificate verification have no equivalent workaround and should upgrade.

References

GHSA-p9jg-fcr6-3mhf — the related com.ongres.scram:scram-client issue (root cause of the empty channel-binding value).
scram-client 3.3 release (library fix): https://github.com/ongres/scram/releases/tag/3.3
pgJDBC fix in 42.7.12: commit

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.postgresql:postgresql`	≥ 42.7.4&&< 42.7.12	42.7.12`org.postgresql:postgresql:42.7.12`

Affected Products

1 product · 1 configurations

Application

postgresql jdbc driverpostgresql

≥ 42.7.4 && < 42.7.12

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.postgresql:postgresql, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.postgresql:postgresql to 42.7.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54291 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Red Hat build of Keycloak 26.4.15	see advisory	RHSA-2026:56520
Red Hat build of Keycloak 26.6.6	see advisory	RHSA-2026:56523
Red Hat build of Quarkus 3.27.5	`postgresql`	RHSA-2026:53643
Red Hat build of Quarkus 3.33.3	`postgresql`	RHSA-2026:51653

Frequently Asked Questions

### 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 em

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