CVE-2026-23300: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-77gg-4hmh-hwxc
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CVSS 5.5
CWE-476
Published
Advisory Summary

CVE-2026-23300 is a MODERATE (CVSS 5.5) security vulnerability vulnerability (CWE-476: NULL Pointer Dereference) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product dereferences a pointer that it expects to be valid but is null.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-23300 at a Glance

CVE Identifier CVE-2026-23300
GHSA Identifier GHSA-77gg-4hmh-hwxc
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-476: NULL Pointer Dereference
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.5

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:N/I:N/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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-23300

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-2026-23300, 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-476: NULL Pointer Dereference, where the product dereferences a pointer that it expects to be valid but is null. 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: net: ipv6: fix panic when IPv4 route references loopback IPv6 nexthop When a standalone IPv6 nexthop object is created with a loopback device (e.g., "ip -6 nexthop add id 100 dev lo"), fib6_nh_init() misclassifies it as a reject route. This is because nexthop objects have no destination prefix (fc_dst=::), causing fib6_is_reject() to match any loopback nexthop. The reject path skips fib_nh_common_init(), leaving nhc_pcpu_rth_output unallocated. If an IPv4 route later references this nexthop, __mkroute_output() dereferences NULL nhc_pcpu_rth_output and panics. Simplify the check in fib6_nh_init() to only match explicit reject routes (RTF_REJECT) instead of using fib6_is_reject(). The loopback promotion heuristic in fib6_is_reject() is handled separately by ip6_route_info_create_nh(). After this change, the three cases behave as follows: 1. Explicit reject route ("ip -6 route add unreachable 2001:db8::/64"): RTF_REJECT is set, enters reject path, skips fib_nh_common_init(). No behavior change. 2. Implicit loopback reject route ("ip -6 route add 2001:db8::/32 dev lo"): RTF_REJECT is not set, takes normal path, fib_nh_common_init() is called. ip6_route_info_create_nh() still promotes it to reject afterward. nhc_pcpu_rth_output is allocated but unused, which is harmless. 3. Standalone nexthop object ("ip -6 nexthop add id 100 dev lo"): RTF_REJECT is not set, takes normal path, fib_nh_common_init() is called. nhc_pcpu_rth_output is properly allocated, fixing the crash when IPv4 routes reference this nexthop.

References

NVD — CVE-2026-23300 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23300
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-457936.html
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-784472.html
git.kernel.org/stable/c/21ec92774d... WEB
https://git.kernel.org/stable/c/21ec92774d1536f71bdc90b0e3d052eff99cf093
git.kernel.org/stable/c/607e68c1b7... WEB
https://git.kernel.org/stable/c/607e68c1b7c5a30c795571be1906d716e989a644
git.kernel.org/stable/c/8650db85b4... WEB
https://git.kernel.org/stable/c/8650db85b4259d2885d2a80fbc2317ce24194133
git.kernel.org/stable/c/b299121e74... WEB
https://git.kernel.org/stable/c/b299121e7453d23faddf464087dff513a495b4fc
git.kernel.org/stable/c/b3b5a037d5... WEB
https://git.kernel.org/stable/c/b3b5a037d520afe3d5276e653bc0ff516bbda34c
git.kernel.org/stable/c/b5062fc215... WEB
https://git.kernel.org/stable/c/b5062fc2150614c9ea8a611c2e0cb6e047ebfa3a
git.kernel.org/stable/c/c11d7c56c2... WEB
https://git.kernel.org/stable/c/c11d7c56c2076ee9cd72004f1976fe0734df2ae9
git.kernel.org/stable/c/f7c9f8e360... WEB
https://git.kernel.org/stable/c/f7c9f8e3607440fe39300efbaf46cf7b5eecb23f

Frequently Asked Questions

What is CVE-2026-23300?
CVE-2026-23300 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-476: NULL Pointer Dereference.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-23300?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-23300?
CVE-2026-23300 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-23300?
CVE-2026-23300 is classified under CWE-476: NULL Pointer Dereference (The product dereferences a pointer that it expects to be valid but is NULL.).
How can I check Maven dependencies for CVE-2026-23300?
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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  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: fix panic when IPv4 route references loopback IPv6 nexthop\n\nWhen a standalone IPv6 nexthop object is created with a loopback device\n(e.g., \"ip -6 nexthop add id 100 dev lo\"), fib6_nh_init() misclassifies\nit as a reject route. This is because nexthop objects have no destination\nprefix (fc_dst=::), causing fib6_is_reject() to match any loopback\nnexthop. The reject path skips fib_nh_common_init(), leaving\nnhc_pcpu_rth_output unallocated. If an IPv4 route later references this\nnexthop, __mkroute_output() dereferences NULL nhc_pcpu_rth_output and\npanics.\n\nSimplify the check in fib6_nh_init() to only match explicit reject\nroutes (RTF_REJECT) instead of using fib6_is_reject(). The loopback\npromotion heuristic in fib6_is_reject() is handled separately by\nip6_route_info_create_nh(). After this change, the three cases behave\nas follows:\n\n1. Explicit reject route (\"ip -6 route add unreachable 2001:db8::/64\"):\n   RTF_REJECT is set, enters reject path, skips fib_nh_common_init().\n   No behavior change.\n\n2. Implicit loopback reject route (\"ip -6 route add 2001:db8::/32 dev lo\"):\n   RTF_REJECT is not set, takes normal path, fib_nh_common_init() is\n   called. ip6_route_info_create_nh() still promotes it to reject\n   afterward. nhc_pcpu_rth_output is allocated but unused, which is\n   harmless.\n\n3. Standalone nexthop object (\"ip -6 nexthop add id 100 dev lo\"):\n   RTF_REJECT is not set, takes normal path, fib_nh_common_init() is\n   called. nhc_pcpu_rth_output is properly allocated, fixing the crash\n   when IPv4 routes reference this nexthop.",
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