CVE-2026-89787: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-cxfp-66mh-jhvv
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Advisory Summary

CVE-2026-89787 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89787 at a Glance

CVE Identifier CVE-2026-89787
GHSA Identifier GHSA-cxfp-66mh-jhvv
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-89787

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-2026-89787, 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: ext4: check dir entry fits before reading the hash trailer in ext4_search_dir() For casefolded encrypted directories ext4 stores an 8-byte hash trailer after the name (EXT4_DIRENT_HASHES()), at an offset derived from de->name_len. On the sb_no_casefold_compat_fallback() path ext4_match() reads that trailer, but ext4_search_dir()'s by-hand pre-check only tests de->name + de->name_len <= dlimit, which proves the name fits, not the rounded trailer. A crafted entry whose name ends at the block boundary passes the check while EXT4_DIRENT_HASHES(de) lands past the block end, so ext4_match() reads out of bounds on an ordinary lookup. KASAN reports it as a use-after-free when the page after the directory block holds a freed object: BUG: KASAN: use-after-free in ext4_match (fs/ext4/namei.c:1435) Read of size 4 at addr ffff888010458000 by task exploit Call Trace: ext4_match (fs/ext4/namei.c:1435) ext4_search_dir (fs/ext4/namei.c:1470) __ext4_find_entry (fs/ext4/namei.c:1268 fs/ext4/namei.c:1632) ext4_lookup (fs/ext4/namei.c:1703 fs/ext4/namei.c:1769) ... filename_lookup (fs/namei.c:2842) vfs_statx (fs/stat.c:353) __do_sys_newfstatat (fs/stat.c:538) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Require, for hash-in-dirent directories, that the whole entry including the rounded trailer fits before calling ext4_match(). This is the same bound ext4_check_dir_entry() already enforces via ext4_dir_rec_len(), so no well-formed entry is rejected. The other caller, ext4_find_dest_de(), runs ext4_check_dir_entry() first and is unaffected.

References

NVD — CVE-2026-89787 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89787
git.kernel.org/stable/c/3933884bc3... WEB
https://git.kernel.org/stable/c/3933884bc3102898b458c53fbd1ac52eb9cdb8a4
git.kernel.org/stable/c/4d20106c53... WEB
https://git.kernel.org/stable/c/4d20106c536b73c4a8a02652dc85e35898baebf7
git.kernel.org/stable/c/61a395967d... WEB
https://git.kernel.org/stable/c/61a395967de06edba58760e81907a272db749faa
git.kernel.org/stable/c/83663c0b73... WEB
https://git.kernel.org/stable/c/83663c0b739480c00cfe785675db87520ec484ed
git.kernel.org/stable/c/c7e6b863d2... WEB
https://git.kernel.org/stable/c/c7e6b863d298f56522d0d08554bbea7f142e6588
git.kernel.org/stable/c/d8c184bec2... WEB
https://git.kernel.org/stable/c/d8c184bec24b5a00ae96d704856d935eaded1685
git.kernel.org/stable/c/e94676a08a... WEB
https://git.kernel.org/stable/c/e94676a08af6312aa72d8a981232b281f9bcfcf5

Frequently Asked Questions

What is CVE-2026-89787?
CVE-2026-89787 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-2026-89787?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-89787?
CVE-2026-89787 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89787?
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-cxfp-66mh-jhvv",
  "modified" : "2026-09-16T09:30:30Z",
  "published" : "2026-09-16T09:30:30Z",
  "aliases" : [ "CVE-2026-89787" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\next4: check dir entry fits before reading the hash trailer in ext4_search_dir()\n\nFor casefolded encrypted directories ext4 stores an 8-byte hash trailer\nafter the name (EXT4_DIRENT_HASHES()), at an offset derived from\nde->name_len.  On the sb_no_casefold_compat_fallback() path ext4_match()\nreads that trailer, but ext4_search_dir()'s by-hand pre-check only tests\nde->name + de->name_len <= dlimit, which proves the name fits, not the\nrounded trailer.  A crafted entry whose name ends at the block boundary\npasses the check while EXT4_DIRENT_HASHES(de) lands past the block end,\nso ext4_match() reads out of bounds on an ordinary lookup.  KASAN reports\nit as a use-after-free when the page after the directory block holds a\nfreed object:\n\n  BUG: KASAN: use-after-free in ext4_match (fs/ext4/namei.c:1435)\n  Read of size 4 at addr ffff888010458000 by task exploit\n  Call Trace:\n   ext4_match (fs/ext4/namei.c:1435)\n   ext4_search_dir (fs/ext4/namei.c:1470)\n   __ext4_find_entry (fs/ext4/namei.c:1268 fs/ext4/namei.c:1632)\n   ext4_lookup (fs/ext4/namei.c:1703 fs/ext4/namei.c:1769)\n   ...\n   filename_lookup (fs/namei.c:2842)\n   vfs_statx (fs/stat.c:353)\n   __do_sys_newfstatat (fs/stat.c:538)\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nRequire, for hash-in-dirent directories, that the whole entry including\nthe rounded trailer fits before calling ext4_match().  This is the same\nbound ext4_check_dir_entry() already enforces via ext4_dir_rec_len(), so\nno well-formed entry is rejected.  The other caller, ext4_find_dest_de(),\nruns ext4_check_dir_entry() first and is unaffected.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89787"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/3933884bc3102898b458c53fbd1ac52eb9cdb8a4"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/4d20106c536b73c4a8a02652dc85e35898baebf7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/61a395967de06edba58760e81907a272db749faa"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/83663c0b739480c00cfe785675db87520ec484ed"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/c7e6b863d298f56522d0d08554bbea7f142e6588"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d8c184bec24b5a00ae96d704856d935eaded1685"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e94676a08af6312aa72d8a981232b281f9bcfcf5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-16T09:17:09Z"
  }
}