CVE-2026-6477: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-jm5f-gpfq-q9h3
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CVSS 8.8
CWE-120 CWE-242
Published
Advisory Summary

CVE-2026-6477 is a HIGH (CVSS 8.8) security vulnerability vulnerability (CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-6477 at a Glance

CVE Identifier CVE-2026-6477
GHSA Identifier GHSA-jm5f-gpfq-q9h3
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-6477

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-6477, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'), where the product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Use of inherently dangerous function PQfn(..., result_is_int=0, ...) in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response. Like gets(), PQfn(..., result_is_int=0, ...) stores arbitrary-length, server-determined data into a buffer of unspecified size. Because both the \lo_export command in psql and pg_dump call lo_read(), the server superuser can overwrite pg_dump or psql stack memory. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

References

NVD — CVE-2026-6477 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6477
access.redhat.com/errata/rhsa-2026:21... WEB
https://access.redhat.com/errata/RHSA-2026:21182
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33497
access.redhat.com/errata/rhsa-2026:34... WEB
https://access.redhat.com/errata/RHSA-2026:34043
access.redhat.com/errata/rhsa-2026:34... WEB
https://access.redhat.com/errata/RHSA-2026:34362
access.redhat.com/errata/rhsa-2026:34... WEB
https://access.redhat.com/errata/RHSA-2026:34363
access.redhat.com/errata/rhsa-2026:35... WEB
https://access.redhat.com/errata/RHSA-2026:35880
access.redhat.com/errata/rhsa-2026:42... WEB
https://access.redhat.com/errata/RHSA-2026:42555
access.redhat.com/errata/rhsa-2026:44... WEB
https://access.redhat.com/errata/RHSA-2026:44308
access.redhat.com/errata/rhsa-2026:44... WEB
https://access.redhat.com/errata/RHSA-2026:44391
access.redhat.com/errata/rhsa-2026:44... WEB
https://access.redhat.com/errata/RHSA-2026:44420
access.redhat.com/errata/rhsa-2026:44... WEB
https://access.redhat.com/errata/RHSA-2026:44481
access.redhat.com/errata/rhsa-2026:47... WEB
https://access.redhat.com/errata/RHSA-2026:47090
access.redhat.com/errata/rhsa-2026:49... WEB
https://access.redhat.com/errata/RHSA-2026:49521
access.redhat.com/errata/rhsa-2026:49... WEB
https://access.redhat.com/errata/RHSA-2026:49908
access.redhat.com/errata/rhsa-2026:49... WEB
https://access.redhat.com/errata/RHSA-2026:49909
access.redhat.com/errata/rhsa-2026:50... WEB
https://access.redhat.com/errata/RHSA-2026:50779
access.redhat.com/errata/rhsa-2026:50... WEB
https://access.redhat.com/errata/RHSA-2026:50863
access.redhat.com/errata/rhsa-2026:54... WEB
https://access.redhat.com/errata/RHSA-2026:54760
access.redhat.com/errata/rhsa-2026:58... WEB
https://access.redhat.com/errata/RHSA-2026:58981
Software Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-6477
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2477442
Software Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6477.json
Software Security Information SECURITY
https://www.postgresql.org/support/security/CVE-2026-6477
access.redhat.com/errata/rhsa-2026:22... WEB
https://access.redhat.com/errata/RHSA-2026:22878
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26181
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26203
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26204
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26524
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26525
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26561
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27718
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27738
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27741
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27742
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27743
access.redhat.com/errata/rhsa-2026:28... WEB
https://access.redhat.com/errata/RHSA-2026:28037
access.redhat.com/errata/rhsa-2026:28... WEB
https://access.redhat.com/errata/RHSA-2026:28143
access.redhat.com/errata/rhsa-2026:28... WEB
https://access.redhat.com/errata/RHSA-2026:28208
access.redhat.com/errata/rhsa-2026:28... WEB
https://access.redhat.com/errata/RHSA-2026:28999
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29212
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29815
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29904
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29953
access.redhat.com/errata/rhsa-2026:32... WEB
https://access.redhat.com/errata/RHSA-2026:32983
access.redhat.com/errata/rhsa-2026:32... WEB
https://access.redhat.com/errata/RHSA-2026:32994
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33441

Frequently Asked Questions

What is CVE-2026-6477?
CVE-2026-6477 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-6477?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-6477?
CVE-2026-6477 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-6477?
CVE-2026-6477 is classified under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') (The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.).
How can I check Maven dependencies for CVE-2026-6477?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
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