CVE-2026-89638: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-7hx7-9jhj-445w
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CVSS 7.8
Published
Advisory Summary

CVE-2026-89638 is a HIGH (CVSS 7.8) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89638 at a Glance

CVE Identifier CVE-2026-89638
GHSA Identifier GHSA-7hx7-9jhj-445w
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.8

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

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

How to Fix CVE-2026-89638

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-2026-89638, 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 General Security Weakness. 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

In the Linux kernel, the following vulnerability has been resolved: smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions When a file has the setuid or setgid bit set and is written to, the VFS strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID together with an ATTR_MODE carrying the already-cleared mode. Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped ATTR_MODE in that case: /* skip mode change if it's just for clearing setuid/setgid */ if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) attrs->ia_valid &= ~ATTR_MODE; This is fine for the default mount, where the mode is only emulated via the DOS read-only attribute and cannot represent the setuid/setgid bits anyway. However, with the "cifsacl" or "modefromsid" mount options the mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with the SMB3.1.1 POSIX extensions the mode is sent to the server directly, and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means the cleared mode is never pushed to the server, so the setuid/setgid bit survives the write. This is a security issue: on local filesystems the setuid bit is stripped when a file is written, but over these cifs.ko mounts the bit persists on the server, potentially allowing an unexpected privilege escalation on subsequent execution. Fix this in two places: 1. cifs_setattr_nounix(): only take the "skip mode change" shortcut when the mode is emulated via the DOS read-only attribute (i.e. neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are in effect), so that the cleared mode is propagated to the server in the ACL / POSIX cases. 2. cifs_setattr_unix(): this function is only called when Unix extensions are in effect, so the mode is always stored on the server. Remove the shortcut entirely so that the cleared mode is always pushed.

References

NVD — CVE-2026-89638 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89638
git.kernel.org/stable/c/58b23fc9fb... WEB
https://git.kernel.org/stable/c/58b23fc9fb580432470d6c5da3c1e5660dba9fbc
git.kernel.org/stable/c/69bfe810ec... WEB
https://git.kernel.org/stable/c/69bfe810ecd1e0387d8975d711cd326341d13c6e
git.kernel.org/stable/c/b10015807e... WEB
https://git.kernel.org/stable/c/b10015807e4c628095d1d1d1c9307efc8cdd9e1b
git.kernel.org/stable/c/b8e5dc4f95... WEB
https://git.kernel.org/stable/c/b8e5dc4f95e5484159b343903f302eb6d783f2e6

Frequently Asked Questions

What is CVE-2026-89638?
CVE-2026-89638 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-89638?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-89638?
CVE-2026-89638 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-89638?
CVE-2026-89638 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89638?
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-7hx7-9jhj-445w",
  "modified" : "2026-10-15T12:30:46Z",
  "published" : "2026-09-11T21:31:34Z",
  "aliases" : [ "CVE-2026-89638" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions\n\nWhen a file has the setuid or setgid bit set and is written to, the VFS\nstrips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID\ntogether with an ATTR_MODE carrying the already-cleared mode.\n\nBoth cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped\nATTR_MODE in that case:\n\n\t/* skip mode change if it's just for clearing setuid/setgid */\n\tif (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))\n\t\tattrs->ia_valid &= ~ATTR_MODE;\n\nThis is fine for the default mount, where the mode is only emulated via\nthe DOS read-only attribute and cannot represent the setuid/setgid bits\nanyway.  However, with the \"cifsacl\" or \"modefromsid\" mount options the\nmode is stored on the server through an ACL (id_mode_to_cifs_acl()), with\nthe SMB3.1.1 POSIX extensions the mode is sent to the server directly,\nand with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent\nvia CIFSSMBUnixSetPathInfo().  In all those cases dropping ATTR_MODE means\nthe cleared mode is never pushed to the server, so the setuid/setgid bit\nsurvives the write.\n\nThis is a security issue: on local filesystems the setuid bit is stripped\nwhen a file is written, but over these cifs.ko mounts the bit persists on\nthe server, potentially allowing an unexpected privilege escalation on\nsubsequent execution.\n\nFix this in two places:\n\n  1. cifs_setattr_nounix(): only take the \"skip mode change\" shortcut\n     when the mode is emulated via the DOS read-only attribute (i.e.\n     neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are\n     in effect), so that the cleared mode is propagated to the server\n     in the ACL / POSIX cases.\n\n  2. cifs_setattr_unix(): this function is only called when Unix\n     extensions are in effect, so the mode is always stored on the\n     server.  Remove the shortcut entirely so that the cleared mode is\n     always pushed.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89638"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/58b23fc9fb580432470d6c5da3c1e5660dba9fbc"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/69bfe810ecd1e0387d8975d711cd326341d13c6e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b10015807e4c628095d1d1d1c9307efc8cdd9e1b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b8e5dc4f95e5484159b343903f302eb6d783f2e6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T20:19:49Z"
  }
}