CVE-2026-86861: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-2wg3-5wmg-5872
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CVSS 5.9
CWE-59
Published
Advisory Summary

CVE-2026-86861 is a MODERATE (CVSS 5.9) security vulnerability vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-86861 at a Glance

CVE Identifier CVE-2026-86861
GHSA Identifier GHSA-2wg3-5wmg-5872
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-59: Improper Link Resolution Before File Access ('Link Following')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.9

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

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

How to Fix CVE-2026-86861

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-2026-86861, 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-59: Improper Link Resolution Before File Access ('Link Following'), where the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. 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

pgAdmin 4's File Manager save_file endpoint, which backs saving from the Query Tool and ERD, validated the requested path with Filemanager.check_access_permission() and then opened the file for writing with a plain open() call. CVE-2026-7819 had previously hardened the separate file upload path by opening its target with O_NOFOLLOW, so that the kernel refuses to follow a symbolic link at the final path component, but save_file was left on an unprotected open(). A symbolic link already present when the check ran was rejected by the check itself; the remaining exposure was a link substituted at the final path component in the interval between the check and the write, at which point the write followed the link and landed outside the user's storage directory, creating or overwriting an arbitrary file as the operating-system account running pgAdmin. Exploitation requires the ability to create or replace a symbolic link inside the requesting user's storage directory. pgAdmin exposes no interface that creates symbolic links, so this requires filesystem access to the pgAdmin host or to a shared or network-mounted storage backend, together with winning the timing window. The reporter did not achieve a write against a released version, having attempted approximately 63,000 racing requests without success; the reported defect is the uncovered write path rather than a demonstrated sandbox escape. The fix routes save_file's write through the same O_NOFOLLOW-protected helper already used by the upload path, so both File Manager write sinks carry identical kernel-enforced protection, and reports a symbolic-link refusal explicitly instead of surfacing the underlying system error text. Note that files created by save_file are now given mode 0600, inheriting the behaviour introduced for uploads. The protection covers the final path component; substitution of an intermediate directory component is not addressed by this change. This issue affects pgAdmin 4: from the introduction of the containment check in the File Manager save path before 9.18.

References

NVD — CVE-2026-86861 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86861
Software Source Repository REPOSITORY
https://github.com/pgadmin-org/pgadmin4/issues/10385

Frequently Asked Questions

What is CVE-2026-86861?
CVE-2026-86861 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-59: Improper Link Resolution Before File Access ('Link Following').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-86861?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-86861?
CVE-2026-86861 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L.
What CWE is associated with CVE-2026-86861?
CVE-2026-86861 is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following') (The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.).
How can I check Maven dependencies for CVE-2026-86861?
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 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2wg3-5wmg-5872",
  "modified" : "2026-09-17T18:31:47Z",
  "published" : "2026-09-17T18:31:47Z",
  "aliases" : [ "CVE-2026-86861" ],
  "details" : "pgAdmin 4's File Manager save_file endpoint, which backs saving from the Query Tool and ERD, validated the requested path with Filemanager.check_access_permission() and then opened the file for writing with a plain open() call. CVE-2026-7819 had previously hardened the separate file upload path by opening its target with O_NOFOLLOW, so that the kernel refuses to follow a symbolic link at the final path component, but save_file was left on an unprotected open(). A symbolic link already present when the check ran was rejected by the check itself; the remaining exposure was a link substituted at the final path component in the interval between the check and the write, at which point the write followed the link and landed outside the user's storage directory, creating or overwriting an arbitrary file as the operating-system account running pgAdmin.\n\nExploitation requires the ability to create or replace a symbolic link inside the requesting user's storage directory. pgAdmin exposes no interface that creates symbolic links, so this requires filesystem access to the pgAdmin host or to a shared or network-mounted storage backend, together with winning the timing window. The reporter did not achieve a write against a released version, having attempted approximately 63,000 racing requests without success; the reported defect is the uncovered write path rather than a demonstrated sandbox escape.\n\nThe fix routes save_file's write through the same O_NOFOLLOW-protected helper already used by the upload path, so both File Manager write sinks carry identical kernel-enforced protection, and reports a symbolic-link refusal explicitly instead of surfacing the underlying system error text. Note that files created by save_file are now given mode 0600, inheriting the behaviour introduced for uploads. The protection covers the final path component; substitution of an intermediate directory component is not addressed by this change.\n\nThis issue affects pgAdmin 4: from the introduction of the containment check in the File Manager save path before 9.18.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-86861"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pgadmin-org/pgadmin4/issues/10385"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-59" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-17T16:18:17Z"
  }
}