CVE-2026-89633: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-6jcv-m8xc-577h
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CVSS 9.8
Published
Advisory Summary

CVE-2026-89633 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89633 at a Glance

CVE Identifier CVE-2026-89633
GHSA Identifier GHSA-6jcv-m8xc-577h
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:N/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 None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-89633

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-2026-89633, 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: fix OOB read/write from unvalidated DataOffset in coalesce_t2() coalesce_t2() computes data pointers directly from server-supplied DataOffset fields with no validation against buffer bounds: data_area_of_tgt = (char *)&pSMBt->hdr.Protocol + get_unaligned_le16(&pSMBt->t2_rsp.DataOffset); data_area_of_src = (char *)&pSMBs->hdr.Protocol + get_unaligned_le16(&pSMBs->t2_rsp.DataOffset); data_area_of_tgt += total_in_tgt; ... memcpy(data_area_of_tgt, data_area_of_src, total_in_src); A small DataOffset can push a pointer below the actual byte area, overwriting header fields; a large one can push it past the buffer end, causing out-of-bounds heap reads (source) or writes (target). The BCC overflow guard does not prevent this: BCC reflects how much data is present, while DataOffset controls where in the buffer it starts. The "validate target area" comment present since the function was first written in 2005 was a placeholder that was never implemented. Add lower- and upper-bound checks for both data pointers before the memcpy, and before any target header fields are modified.

References

NVD — CVE-2026-89633 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89633
git.kernel.org/stable/c/033bc80019... WEB
https://git.kernel.org/stable/c/033bc80019f07d158630df4e69b19a49010f54f1
git.kernel.org/stable/c/36d01415d8... WEB
https://git.kernel.org/stable/c/36d01415d881d5326a0dd3384f781cd7e69aff2d
git.kernel.org/stable/c/6343c1da56... WEB
https://git.kernel.org/stable/c/6343c1da561962688f203362d80d6a3bfa39fa1b
git.kernel.org/stable/c/672cf86aa6... WEB
https://git.kernel.org/stable/c/672cf86aa6aa0fb4012ce4c3b3498df42ad67a4e

Frequently Asked Questions

What is CVE-2026-89633?
CVE-2026-89633 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-2026-89633?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-89633?
CVE-2026-89633 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-89633?
CVE-2026-89633 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89633?
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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  "schema_version" : "1.4.0",
  "id" : "GHSA-6jcv-m8xc-577h",
  "modified" : "2026-10-15T12:30:46Z",
  "published" : "2026-09-11T21:31:34Z",
  "aliases" : [ "CVE-2026-89633" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2()\n\ncoalesce_t2() computes data pointers directly from server-supplied\nDataOffset fields with no validation against buffer bounds:\n\n  data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +\n                     get_unaligned_le16(&pSMBt->t2_rsp.DataOffset);\n  data_area_of_src = (char *)&pSMBs->hdr.Protocol +\n                     get_unaligned_le16(&pSMBs->t2_rsp.DataOffset);\n  data_area_of_tgt += total_in_tgt;\n  ...\n  memcpy(data_area_of_tgt, data_area_of_src, total_in_src);\n\nA small DataOffset can push a pointer below the actual byte area,\noverwriting header fields; a large one can push it past the buffer\nend, causing out-of-bounds heap reads (source) or writes (target).\nThe BCC overflow guard does not prevent this: BCC reflects how much\ndata is present, while DataOffset controls where in the buffer it\nstarts.\n\nThe \"validate target area\" comment present since the function was\nfirst written in 2005 was a placeholder that was never implemented.\n\nAdd lower- and upper-bound checks for both data pointers before the\nmemcpy, and before any target header fields are modified.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89633"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/033bc80019f07d158630df4e69b19a49010f54f1"
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  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/6343c1da561962688f203362d80d6a3bfa39fa1b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/672cf86aa6aa0fb4012ce4c3b3498df42ad67a4e"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T20:19:48Z"
  }
}