CVE-2025-40186: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-qx52-pj36-489j
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CVSS 8.1
Published
Advisory Summary

CVE-2025-40186 is a HIGH (CVSS 8.1) security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2025-40186 at a Glance

CVE Identifier CVE-2025-40186
GHSA Identifier GHSA-qx52-pj36-489j
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
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-2025-40186

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-2025-40186, 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: tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request(). syzbot reported the splat below in tcp_conn_request(). [0] If a listener is close()d while a TFO socket is being processed in tcp_conn_request(), inet_csk_reqsk_queue_add() does not set reqsk->sk and calls inet_child_forget(), which calls tcp_disconnect() for the TFO socket. After the cited commit, tcp_disconnect() calls reqsk_fastopen_remove(), where reqsk_put() is called due to !reqsk->sk. Then, reqsk_fastopen_remove() in tcp_conn_request() decrements the last req->rsk_refcnt and frees reqsk, and __reqsk_free() at the drop_and_free label causes the refcount underflow for the listener and double-free of the reqsk. Let's remove reqsk_fastopen_remove() in tcp_conn_request(). Note that other callers make sure tp->fastopen_rsk is not NULL. [0]: refcount_t: underflow; use-after-free. WARNING: CPU: 12 PID: 5563 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28) Modules linked in: CPU: 12 UID: 0 PID: 5563 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:refcount_warn_saturate (lib/refcount.c:28) Code: ab e8 8e b4 98 ff 0f 0b c3 cc cc cc cc cc 80 3d a4 e4 d6 01 00 75 9c c6 05 9b e4 d6 01 01 48 c7 c7 e8 df fb ab e8 6a b4 98 ff <0f> 0b e9 03 5b 76 00 cc 80 3d 7d e4 d6 01 00 0f 85 74 ff ff ff c6 RSP: 0018:ffffa79fc0304a98 EFLAGS: 00010246 RAX: d83af4db1c6b3900 RBX: ffff9f65c7a69020 RCX: d83af4db1c6b3900 RDX: 0000000000000000 RSI: 00000000ffff7fff RDI: ffffffffac78a280 RBP: 000000009d781b60 R08: 0000000000007fff R09: ffffffffac6ca280 R10: 0000000000017ffd R11: 0000000000000004 R12: ffff9f65c7b4f100 R13: ffff9f65c7d23c00 R14: ffff9f65c7d26000 R15: ffff9f65c7a64ef8 FS: 00007f9f962176c0(0000) GS:ffff9f65fcf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000180 CR3: 000000000dbbe006 CR4: 0000000000372ef0 Call Trace: <IRQ> tcp_conn_request (./include/linux/refcount.h:400 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/sock.h:1965 ./include/net/request_sock.h:131 net/ipv4/tcp_input.c:7301) tcp_rcv_state_process (net/ipv4/tcp_input.c:6708) tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1670) tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1906) ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:438) ip6_input (net/ipv6/ip6_input.c:500) ipv6_rcv (net/ipv6/ip6_input.c:311) __netif_receive_skb (net/core/dev.c:6104) process_backlog (net/core/dev.c:6456) __napi_poll (net/core/dev.c:7506) net_rx_action (net/core/dev.c:7569 net/core/dev.c:7696) handle_softirqs (kernel/softirq.c:579) do_softirq (kernel/softirq.c:480) </IRQ>

References

NVD — CVE-2025-40186 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-40186
git.kernel.org/stable/c/2e7cbbbe3d... WEB
https://git.kernel.org/stable/c/2e7cbbbe3d61c63606994b7ff73c72537afe2e1c
git.kernel.org/stable/c/422c1c173c... WEB
https://git.kernel.org/stable/c/422c1c173c39bbbae1e0eaaf8aefe40b2596233b
git.kernel.org/stable/c/643a94b0cf... WEB
https://git.kernel.org/stable/c/643a94b0cf767325e953591c212be2eb826b9d7f
git.kernel.org/stable/c/64dc47a13a... WEB
https://git.kernel.org/stable/c/64dc47a13aa3d9daf7cec29b44dca8e22a6aea15
git.kernel.org/stable/c/c11ace909e... WEB
https://git.kernel.org/stable/c/c11ace909e873118295e9eb22dc8c58b0b50eb32
git.kernel.org/stable/c/e359b742ea... WEB
https://git.kernel.org/stable/c/e359b742eac1eac75cff4e38ee2e8cea492acd9b
git.kernel.org/stable/c/eb85ad5f23... WEB
https://git.kernel.org/stable/c/eb85ad5f23268d64b037bfb545cbcba3752f90c7
git.kernel.org/stable/c/ff6a8883f9... WEB
https://git.kernel.org/stable/c/ff6a8883f96a5bc74241ce5b3d431a6dcfa2124d

Frequently Asked Questions

What is CVE-2025-40186?
CVE-2025-40186 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-2025-40186?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2025-40186?
CVE-2025-40186 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2025-40186?
CVE-2025-40186 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2025-40186?
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-qx52-pj36-489j",
  "modified" : "2026-07-30T06:32:17Z",
  "published" : "2025-11-13T00:30:17Z",
  "aliases" : [ "CVE-2025-40186" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: Don't call reqsk_fastopen_remove() in tcp_conn_request().\n\nsyzbot reported the splat below in tcp_conn_request(). [0]\n\nIf a listener is close()d while a TFO socket is being processed in\ntcp_conn_request(), inet_csk_reqsk_queue_add() does not set reqsk->sk\nand calls inet_child_forget(), which calls tcp_disconnect() for the\nTFO socket.\n\nAfter the cited commit, tcp_disconnect() calls reqsk_fastopen_remove(),\nwhere reqsk_put() is called due to !reqsk->sk.\n\nThen, reqsk_fastopen_remove() in tcp_conn_request() decrements the\nlast req->rsk_refcnt and frees reqsk, and __reqsk_free() at the\ndrop_and_free label causes the refcount underflow for the listener\nand double-free of the reqsk.\n\nLet's remove reqsk_fastopen_remove() in tcp_conn_request().\n\nNote that other callers make sure tp->fastopen_rsk is not NULL.\n\n[0]:\nrefcount_t: underflow; use-after-free.\nWARNING: CPU: 12 PID: 5563 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28)\nModules linked in:\nCPU: 12 UID: 0 PID: 5563 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025\nRIP: 0010:refcount_warn_saturate (lib/refcount.c:28)\nCode: ab e8 8e b4 98 ff 0f 0b c3 cc cc cc cc cc 80 3d a4 e4 d6 01 00 75 9c c6 05 9b e4 d6 01 01 48 c7 c7 e8 df fb ab e8 6a b4 98 ff <0f> 0b e9 03 5b 76 00 cc 80 3d 7d e4 d6 01 00 0f 85 74 ff ff ff c6\nRSP: 0018:ffffa79fc0304a98 EFLAGS: 00010246\nRAX: d83af4db1c6b3900 RBX: ffff9f65c7a69020 RCX: d83af4db1c6b3900\nRDX: 0000000000000000 RSI: 00000000ffff7fff RDI: ffffffffac78a280\nRBP: 000000009d781b60 R08: 0000000000007fff R09: ffffffffac6ca280\nR10: 0000000000017ffd R11: 0000000000000004 R12: ffff9f65c7b4f100\nR13: ffff9f65c7d23c00 R14: ffff9f65c7d26000 R15: ffff9f65c7a64ef8\nFS:  00007f9f962176c0(0000) GS:ffff9f65fcf00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000200000000180 CR3: 000000000dbbe006 CR4: 0000000000372ef0\nCall Trace:\n <IRQ>\n tcp_conn_request (./include/linux/refcount.h:400 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/sock.h:1965 ./include/net/request_sock.h:131 net/ipv4/tcp_input.c:7301)\n tcp_rcv_state_process (net/ipv4/tcp_input.c:6708)\n tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1670)\n tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1906)\n ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:438)\n ip6_input (net/ipv6/ip6_input.c:500)\n ipv6_rcv (net/ipv6/ip6_input.c:311)\n __netif_receive_skb (net/core/dev.c:6104)\n process_backlog (net/core/dev.c:6456)\n __napi_poll (net/core/dev.c:7506)\n net_rx_action (net/core/dev.c:7569 net/core/dev.c:7696)\n handle_softirqs (kernel/softirq.c:579)\n do_softirq (kernel/softirq.c:480)\n </IRQ>",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-40186"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/2e7cbbbe3d61c63606994b7ff73c72537afe2e1c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/422c1c173c39bbbae1e0eaaf8aefe40b2596233b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/643a94b0cf767325e953591c212be2eb826b9d7f"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/64dc47a13aa3d9daf7cec29b44dca8e22a6aea15"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/c11ace909e873118295e9eb22dc8c58b0b50eb32"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/e359b742eac1eac75cff4e38ee2e8cea492acd9b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/eb85ad5f23268d64b037bfb545cbcba3752f90c7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ff6a8883f96a5bc74241ce5b3d431a6dcfa2124d"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2025-11-12T22:15:45Z"
  }
}