CVE-2026-89555: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-6h6h-gvhm-2hwq
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CVSS 9.8
Published
Advisory Summary

CVE-2026-89555 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-2026-89555 at a Glance

CVE Identifier CVE-2026-89555
GHSA Identifier GHSA-6h6h-gvhm-2hwq
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-2026-89555

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-2026-89555, 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: mpls: reload header after pskb_may_pull() mpls_select_multipath() calls mpls_multipath_hash() to choose a nexthop when an MPLS route has multiple nexthops. While walking the MPLS label stack, the hash routine caches hdr for the current label. After finding the bottom-of-stack label, it calls pskb_may_pull() before reading the inner IP header. If an skb is constructed with the inner IP header in nonlinear data and insufficient tailroom in the linear head, pskb_may_pull() calls pskb_expand_head() to replace the skb head and free the old one. This leaves hdr pointing to freed memory. The IPv6 path can invalidate hdr again when it performs a second pull for the larger header. The issue was found through static analysis. A reproducer sending a legal Geneve packet through a bareudp/MPLS multipath setup triggered the same KASAN report in 2 of 2 unpatched runs: BUG: KASAN: slab-use-after-free in mpls_select_multipath Read of size 1 at addr ffff88800ecc6e20 by task ksoftirqd/1/23 Call Trace: mpls_select_multipath mpls_forward __netif_receive_skb_list_core netif_receive_skb_list_internal napi_complete_done gro_cell_poll __napi_poll net_rx_action Freed by task 23: kfree pskb_expand_head __pskb_pull_tail mpls_select_multipath Reload hdr from the current skb head after each successful pull before deriving the inner IPv4 or IPv6 header pointer.

References

NVD — CVE-2026-89555 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89555
git.kernel.org/stable/c/29e63b8d9f... WEB
https://git.kernel.org/stable/c/29e63b8d9fc150cc191b1c6eb7e16e1247e1b650
git.kernel.org/stable/c/49d38c1b43... WEB
https://git.kernel.org/stable/c/49d38c1b4390412f8950d33dfaee0ccbd17beb81
git.kernel.org/stable/c/aa4fe0b450... WEB
https://git.kernel.org/stable/c/aa4fe0b450a461aa1162fe8375f5d28f4c957df8
git.kernel.org/stable/c/b1c0783b2f... WEB
https://git.kernel.org/stable/c/b1c0783b2facc398437ad8f8b86c636d7a78f8db
git.kernel.org/stable/c/bfaaff9923... WEB
https://git.kernel.org/stable/c/bfaaff99238326166694354a63a76c02563f98b1
git.kernel.org/stable/c/d82b90a38c... WEB
https://git.kernel.org/stable/c/d82b90a38c2ca8a0694428eab0e9551c23f2447d
git.kernel.org/stable/c/d964023982... WEB
https://git.kernel.org/stable/c/d9640239827d6d0cb84263b590f7a4f1596c17eb
git.kernel.org/stable/c/fed638a248... WEB
https://git.kernel.org/stable/c/fed638a248116b8a249bd4202d28e5934bdc65ad

Frequently Asked Questions

What is CVE-2026-89555?
CVE-2026-89555 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-2026-89555?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-89555?
CVE-2026-89555 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-2026-89555?
CVE-2026-89555 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89555?
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-6h6h-gvhm-2hwq",
  "modified" : "2026-09-14T15:32:29Z",
  "published" : "2026-09-11T21:31:32Z",
  "aliases" : [ "CVE-2026-89555" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nmpls: reload header after pskb_may_pull()\n\nmpls_select_multipath() calls mpls_multipath_hash() to choose a nexthop\nwhen an MPLS route has multiple nexthops.  While walking the MPLS label\nstack, the hash routine caches hdr for the current label.  After finding\nthe bottom-of-stack label, it calls pskb_may_pull() before reading the\ninner IP header.\n\nIf an skb is constructed with the inner IP header in nonlinear data and\ninsufficient tailroom in the linear head, pskb_may_pull() calls\npskb_expand_head() to replace the skb head and free the old one.  This\nleaves hdr pointing to freed memory.  The IPv6 path can invalidate hdr\nagain when it performs a second pull for the larger header.\n\nThe issue was found through static analysis.  A reproducer sending a legal\nGeneve packet through a bareudp/MPLS multipath setup triggered the same\nKASAN report in 2 of 2 unpatched runs:\n\n  BUG: KASAN: slab-use-after-free in mpls_select_multipath\n  Read of size 1 at addr ffff88800ecc6e20 by task ksoftirqd/1/23\n\n  Call Trace:\n   mpls_select_multipath\n   mpls_forward\n   __netif_receive_skb_list_core\n   netif_receive_skb_list_internal\n   napi_complete_done\n   gro_cell_poll\n   __napi_poll\n   net_rx_action\n\n  Freed by task 23:\n   kfree\n   pskb_expand_head\n   __pskb_pull_tail\n   mpls_select_multipath\n\nReload hdr from the current skb head after each successful pull before\nderiving the inner IPv4 or IPv6 header pointer.",
  "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-2026-89555"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/29e63b8d9fc150cc191b1c6eb7e16e1247e1b650"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/49d38c1b4390412f8950d33dfaee0ccbd17beb81"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/aa4fe0b450a461aa1162fe8375f5d28f4c957df8"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b1c0783b2facc398437ad8f8b86c636d7a78f8db"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/bfaaff99238326166694354a63a76c02563f98b1"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d82b90a38c2ca8a0694428eab0e9551c23f2447d"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d9640239827d6d0cb84263b590f7a4f1596c17eb"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/fed638a248116b8a249bd4202d28e5934bdc65ad"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-11T20:19:39Z"
  }
}