CVE-2026-31503: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-8g49-x5x5-4c9c
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CVSS 5.5
Published
Advisory Summary

CVE-2026-31503 is a MODERATE (CVSS 5.5) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-31503 at a Glance

CVE Identifier CVE-2026-31503
GHSA Identifier GHSA-8g49-x5x5-4c9c
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification General Security Weakness
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-2026-31503

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-2026-31503, 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: udp: Fix wildcard bind conflict check when using hash2 When binding a udp_sock to a local address and port, UDP uses two hashes (udptable->hash and udptable->hash2) for collision detection. The current code switches to "hash2" when hslot->count > 10. "hash2" is keyed by local address and local port. "hash" is keyed by local port only. The issue can be shown in the following bind sequence (pseudo code): bind(fd1, "[fd00::1]:8888") bind(fd2, "[fd00::2]:8888") bind(fd3, "[fd00::3]:8888") bind(fd4, "[fd00::4]:8888") bind(fd5, "[fd00::5]:8888") bind(fd6, "[fd00::6]:8888") bind(fd7, "[fd00::7]:8888") bind(fd8, "[fd00::8]:8888") bind(fd9, "[fd00::9]:8888") bind(fd10, "[fd00::10]:8888") /* Correctly return -EADDRINUSE because "hash" is used * instead of "hash2". udp_lib_lport_inuse() detects the * conflict. */ bind(fail_fd, "[::]:8888") /* After one more socket is bound to "[fd00::11]:8888", * hslot->count exceeds 10 and "hash2" is used instead. */ bind(fd11, "[fd00::11]:8888") bind(fail_fd, "[::]:8888") /* succeeds unexpectedly */ The same issue applies to the IPv4 wildcard address "0.0.0.0" and the IPv4-mapped wildcard address "::ffff:0.0.0.0". For example, if there are existing sockets bound to "192.168.1.[1-11]:8888", then binding "0.0.0.0:8888" or "[::ffff:0.0.0.0]:8888" can also miss the conflict when hslot->count > 10. TCP inet_csk_get_port() already has the correct check in inet_use_bhash2_on_bind(). Rename it to inet_use_hash2_on_bind() and move it to inet_hashtables.h so udp.c can reuse it in this fix.

References

NVD — CVE-2026-31503 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31503
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
git.kernel.org/stable/c/0a360f7f73... WEB
https://git.kernel.org/stable/c/0a360f7f73a06ac88f18917055fbcc79694252d7
git.kernel.org/stable/c/18d84c45de... WEB
https://git.kernel.org/stable/c/18d84c45def3671d5c89fbdd5d4ab8a3217fe4b4
git.kernel.org/stable/c/2297e38114... WEB
https://git.kernel.org/stable/c/2297e38114316b26ae02f2d205c49b5511c5ed55
git.kernel.org/stable/c/d6ace0dbcb... WEB
https://git.kernel.org/stable/c/d6ace0dbcbb7fd285738bb87b42b71b01858c952
git.kernel.org/stable/c/e537dd15d0... WEB
https://git.kernel.org/stable/c/e537dd15d0d4ad989d56a1021290f0c674dd8b28
git.kernel.org/stable/c/f1bed05a83... WEB
https://git.kernel.org/stable/c/f1bed05a832ae79be5f7a105da56810eaa59a5f1

Frequently Asked Questions

What is CVE-2026-31503?
CVE-2026-31503 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-2026-31503?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-31503?
CVE-2026-31503 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-2026-31503?
CVE-2026-31503 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-31503?
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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  "id" : "GHSA-8g49-x5x5-4c9c",
  "modified" : "2026-10-15T03:35:37Z",
  "published" : "2026-04-22T15:31:43Z",
  "aliases" : [ "CVE-2026-31503" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nudp: Fix wildcard bind conflict check when using hash2\n\nWhen binding a udp_sock to a local address and port, UDP uses\ntwo hashes (udptable->hash and udptable->hash2) for collision\ndetection. The current code switches to \"hash2\" when\nhslot->count > 10.\n\n\"hash2\" is keyed by local address and local port.\n\"hash\" is keyed by local port only.\n\nThe issue can be shown in the following bind sequence (pseudo code):\n\nbind(fd1,  \"[fd00::1]:8888\")\nbind(fd2,  \"[fd00::2]:8888\")\nbind(fd3,  \"[fd00::3]:8888\")\nbind(fd4,  \"[fd00::4]:8888\")\nbind(fd5,  \"[fd00::5]:8888\")\nbind(fd6,  \"[fd00::6]:8888\")\nbind(fd7,  \"[fd00::7]:8888\")\nbind(fd8,  \"[fd00::8]:8888\")\nbind(fd9,  \"[fd00::9]:8888\")\nbind(fd10, \"[fd00::10]:8888\")\n\n/* Correctly return -EADDRINUSE because \"hash\" is used\n * instead of \"hash2\". udp_lib_lport_inuse() detects the\n * conflict.\n */\nbind(fail_fd, \"[::]:8888\")\n\n/* After one more socket is bound to \"[fd00::11]:8888\",\n * hslot->count exceeds 10 and \"hash2\" is used instead.\n */\nbind(fd11, \"[fd00::11]:8888\")\nbind(fail_fd, \"[::]:8888\")      /* succeeds unexpectedly */\n\nThe same issue applies to the IPv4 wildcard address \"0.0.0.0\"\nand the IPv4-mapped wildcard address \"::ffff:0.0.0.0\". For\nexample, if there are existing sockets bound to\n\"192.168.1.[1-11]:8888\", then binding \"0.0.0.0:8888\" or\n\"[::ffff:0.0.0.0]:8888\" can also miss the conflict when\nhslot->count > 10.\n\nTCP inet_csk_get_port() already has the correct check in\ninet_use_bhash2_on_bind(). Rename it to\ninet_use_hash2_on_bind() and move it to inet_hashtables.h\nso udp.c can reuse it in this fix.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
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    "type" : "ADVISORY",
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    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/0a360f7f73a06ac88f18917055fbcc79694252d7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/18d84c45def3671d5c89fbdd5d4ab8a3217fe4b4"
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    "url" : "https://git.kernel.org/stable/c/e537dd15d0d4ad989d56a1021290f0c674dd8b28"
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    "url" : "https://git.kernel.org/stable/c/f1bed05a832ae79be5f7a105da56810eaa59a5f1"
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  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-04-22T14:16:48Z"
  }
}