CVE-2025-39756: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-vv89-4q7p-gwx6
Share
CVSS 5.5
CWE-401
Published
Advisory Summary

CVE-2025-39756 is a MODERATE (CVSS 5.5) security vulnerability vulnerability (CWE-401: Missing Release of Memory after Effective Lifetime) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.. Remediation is available in the latest vendor maintenance releases.

CVE-2025-39756 at a Glance

CVE Identifier CVE-2025-39756
GHSA Identifier GHSA-vv89-4q7p-gwx6
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-401: Missing Release of Memory after Effective Lifetime
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-2025-39756

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-2025-39756, 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-401: Missing Release of Memory after Effective Lifetime, where the product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. 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: fs: Prevent file descriptor table allocations exceeding INT_MAX When sysctl_nr_open is set to a very high value (for example, 1073741816 as set by systemd), processes attempting to use file descriptors near the limit can trigger massive memory allocation attempts that exceed INT_MAX, resulting in a WARNING in mm/slub.c: WARNING: CPU: 0 PID: 44 at mm/slub.c:5027 __kvmalloc_node_noprof+0x21a/0x288 This happens because kvmalloc_array() and kvmalloc() check if the requested size exceeds INT_MAX and emit a warning when the allocation is not flagged with __GFP_NOWARN. Specifically, when nr_open is set to 1073741816 (0x3ffffff8) and a process calls dup2(oldfd, 1073741880), the kernel attempts to allocate: - File descriptor array: 1073741880 * 8 bytes = 8,589,935,040 bytes - Multiple bitmaps: ~400MB - Total allocation size: > 8GB (exceeding INT_MAX = 2,147,483,647) Reproducer: 1. Set /proc/sys/fs/nr_open to 1073741816: # echo 1073741816 > /proc/sys/fs/nr_open 2. Run a program that uses a high file descriptor: #include <unistd.h> #include <sys/resource.h> int main() { struct rlimit rlim = {1073741824, 1073741824}; setrlimit(RLIMIT_NOFILE, &rlim); dup2(2, 1073741880); // Triggers the warning return 0; } 3. Observe WARNING in dmesg at mm/slub.c:5027 systemd commit a8b627a introduced automatic bumping of fs.nr_open to the maximum possible value. The rationale was that systems with memory control groups (memcg) no longer need separate file descriptor limits since memory is properly accounted. However, this change overlooked that: 1. The kernel's allocation functions still enforce INT_MAX as a maximum size regardless of memcg accounting 2. Programs and tests that legitimately test file descriptor limits can inadvertently trigger massive allocations 3. The resulting allocations (>8GB) are impractical and will always fail systemd's algorithm starts with INT_MAX and keeps halving the value until the kernel accepts it. On most systems, this results in nr_open being set to 1073741816 (0x3ffffff8), which is just under 1GB of file descriptors. While processes rarely use file descriptors near this limit in normal operation, certain selftests (like tools/testing/selftests/core/unshare_test.c) and programs that test file descriptor limits can trigger this issue. Fix this by adding a check in alloc_fdtable() to ensure the requested allocation size does not exceed INT_MAX. This causes the operation to fail with -EMFILE instead of triggering a kernel warning and avoids the impractical >8GB memory allocation request.

References

NVD — CVE-2025-39756 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-39756
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-032379.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/04a2c4b451... WEB
https://git.kernel.org/stable/c/04a2c4b4511d186b0fce685da21085a5d4acd370
git.kernel.org/stable/c/237e416eb6... WEB
https://git.kernel.org/stable/c/237e416eb62101f21b28c9e6e564d10efe1ecc6f
git.kernel.org/stable/c/628fc28f42... WEB
https://git.kernel.org/stable/c/628fc28f42d979f36dbf75a6129ac7730e30c04e
git.kernel.org/stable/c/7495280866... WEB
https://git.kernel.org/stable/c/749528086620f8012b83ae032a80f6ffa80c45cd
git.kernel.org/stable/c/9f61fa6a2a... WEB
https://git.kernel.org/stable/c/9f61fa6a2a89a610120bc4e5d24379c667314b5c
git.kernel.org/stable/c/b4159c5a90... WEB
https://git.kernel.org/stable/c/b4159c5a90c03f8acd3de345a7f5fc63b0909818
git.kernel.org/stable/c/d4f9351243... WEB
https://git.kernel.org/stable/c/d4f9351243c17865a8cdbe6b3ccd09d0b13a7bcc
git.kernel.org/stable/c/dfd1f4ea98... WEB
https://git.kernel.org/stable/c/dfd1f4ea98c3bd3a03d12169b5b2daa1f0a3e4ae
git.kernel.org/stable/c/f95638a8f2... WEB
https://git.kernel.org/stable/c/f95638a8f22eba307dceddf5aef9ae2326bbcf98
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html

Frequently Asked Questions

What is CVE-2025-39756?
CVE-2025-39756 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-401: Missing Release of Memory after Effective Lifetime.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2025-39756?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2025-39756?
CVE-2025-39756 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-2025-39756?
CVE-2025-39756 is classified under CWE-401: Missing Release of Memory after Effective Lifetime (The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.).
How can I check Maven dependencies for CVE-2025-39756?
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-vv89-4q7p-gwx6",
  "modified" : "2026-10-15T03:34:57Z",
  "published" : "2025-09-11T18:35:51Z",
  "aliases" : [ "CVE-2025-39756" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nfs: Prevent file descriptor table allocations exceeding INT_MAX\n\nWhen sysctl_nr_open is set to a very high value (for example, 1073741816\nas set by systemd), processes attempting to use file descriptors near\nthe limit can trigger massive memory allocation attempts that exceed\nINT_MAX, resulting in a WARNING in mm/slub.c:\n\n  WARNING: CPU: 0 PID: 44 at mm/slub.c:5027 __kvmalloc_node_noprof+0x21a/0x288\n\nThis happens because kvmalloc_array() and kvmalloc() check if the\nrequested size exceeds INT_MAX and emit a warning when the allocation is\nnot flagged with __GFP_NOWARN.\n\nSpecifically, when nr_open is set to 1073741816 (0x3ffffff8) and a\nprocess calls dup2(oldfd, 1073741880), the kernel attempts to allocate:\n- File descriptor array: 1073741880 * 8 bytes = 8,589,935,040 bytes\n- Multiple bitmaps: ~400MB\n- Total allocation size: > 8GB (exceeding INT_MAX = 2,147,483,647)\n\nReproducer:\n1. Set /proc/sys/fs/nr_open to 1073741816:\n   # echo 1073741816 > /proc/sys/fs/nr_open\n\n2. Run a program that uses a high file descriptor:\n   #include <unistd.h>\n   #include <sys/resource.h>\n\n   int main() {\n       struct rlimit rlim = {1073741824, 1073741824};\n       setrlimit(RLIMIT_NOFILE, &rlim);\n       dup2(2, 1073741880);  // Triggers the warning\n       return 0;\n   }\n\n3. Observe WARNING in dmesg at mm/slub.c:5027\n\nsystemd commit a8b627a introduced automatic bumping of fs.nr_open to the\nmaximum possible value. The rationale was that systems with memory\ncontrol groups (memcg) no longer need separate file descriptor limits\nsince memory is properly accounted. However, this change overlooked\nthat:\n\n1. The kernel's allocation functions still enforce INT_MAX as a maximum\n   size regardless of memcg accounting\n2. Programs and tests that legitimately test file descriptor limits can\n   inadvertently trigger massive allocations\n3. The resulting allocations (>8GB) are impractical and will always fail\n\nsystemd's algorithm starts with INT_MAX and keeps halving the value\nuntil the kernel accepts it. On most systems, this results in nr_open\nbeing set to 1073741816 (0x3ffffff8), which is just under 1GB of file\ndescriptors.\n\nWhile processes rarely use file descriptors near this limit in normal\noperation, certain selftests (like\ntools/testing/selftests/core/unshare_test.c) and programs that test file\ndescriptor limits can trigger this issue.\n\nFix this by adding a check in alloc_fdtable() to ensure the requested\nallocation size does not exceed INT_MAX. This causes the operation to\nfail with -EMFILE instead of triggering a kernel warning and avoids the\nimpractical >8GB memory allocation request.",
  "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" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-39756"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-032379.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/04a2c4b4511d186b0fce685da21085a5d4acd370"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/237e416eb62101f21b28c9e6e564d10efe1ecc6f"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/628fc28f42d979f36dbf75a6129ac7730e30c04e"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/749528086620f8012b83ae032a80f6ffa80c45cd"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/9f61fa6a2a89a610120bc4e5d24379c667314b5c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b4159c5a90c03f8acd3de345a7f5fc63b0909818"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/d4f9351243c17865a8cdbe6b3ccd09d0b13a7bcc"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/dfd1f4ea98c3bd3a03d12169b5b2daa1f0a3e4ae"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/f95638a8f22eba307dceddf5aef9ae2326bbcf98"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-401" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2025-09-11T17:15:39Z"
  }
}