CVE-2026-72166: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-m993-rm7r-56rw
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Advisory Summary

CVE-2026-72166 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-72166 at a Glance

CVE Identifier CVE-2026-72166
GHSA Identifier GHSA-m993-rm7r-56rw
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-72166

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-2026-72166, 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: net/9p: fix infinite loop in p9_client_rpc on fatal signal When p9_client_rpc() is called with type P9_TFLUSH and the transport has no peer (e.g. fd transport backed by pipes with no 9p server), a fatal signal causes an infinite loop: again: err = io_wait_event_killable(req->wq, ...) /* SIGKILL wakes the task, returns -ERESTARTSYS */ if (err == -ERESTARTSYS && c->status == Connected && type == P9_TFLUSH) { sigpending = 1; clear_thread_flag(TIF_SIGPENDING); goto again; } clear_thread_flag() clears TIF_SIGPENDING before jumping back to io_wait_event_killable(). signal_pending_state() checks TIF_SIGPENDING, finds it zero, and the task goes to sleep again. The task can only wake on the next signal delivery that calls signal_wake_up() and sets TIF_SIGPENDING again. When that happens the loop repeats, clears TIF_SIGPENDING, and sleeps again indefinitely. This is triggered in practice by coredump_wait(): when a thread in a multi-threaded process causes a coredump (e.g. via SIGSYS from Syscall User Dispatch), coredump_wait() sends SIGKILL to all other threads and waits for them to call mm_release(). If one of those threads is blocked in p9_client_rpc() over an fd transport with no peer, it enters the P9_TFLUSH loop and never calls mm_release(), so coredump_wait() stalls forever: INFO: task syz.0.18:676 blocked for more than 143 seconds. Not tainted 6.12.77+ #1 task:syz.0.18 state:D stack:27600 pid:676 tgid:673 ppid:630 flags:0x00000004 Call Trace: <TASK> context_switch kernel/sched/core.c:5344 [inline] __schedule+0xcb4/0x5d50 kernel/sched/core.c:6724 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe5/0x350 kernel/sched/core.c:6816 schedule_timeout+0x253/0x290 kernel/time/timer.c:2593 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x409/0x600 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1d/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:448 [inline] do_coredump+0x854/0x4350 fs/coredump.c:629 get_signal+0x1425/0x2730 kernel/signal.c:2903 arch_do_signal_or_restart+0x81/0x880 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xf9/0x160 kernel/entry/common.c:218 do_syscall_64+0x102/0x220 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Fix: check fatal_signal_pending() before clearing TIF_SIGPENDING in the P9_TFLUSH retry loop. At that point TIF_SIGPENDING is still set, so fatal_signal_pending() works correctly. If a fatal signal is pending, jump to recalc_sigpending to restore TIF_SIGPENDING and return -ERESTARTSYS to the caller. The same defect is present in stable kernels back to 5.4. On those kernels the infinite loop is broken earlier by a second SIGKILL from the parent process (e.g. kill_and_wait() retrying after a timeout), resulting in a zombie process and a shutdown delay rather than a permanent D-state hang, but the underlying flaw is the same. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

References

NVD — CVE-2026-72166 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-72166
git.kernel.org/stable/c/18a3427526... WEB
https://git.kernel.org/stable/c/18a3427526e2141f80050f82c1d26b19a454707d
git.kernel.org/stable/c/378481cc60... WEB
https://git.kernel.org/stable/c/378481cc60a937ef8ea4ef6e4f95f0dbc4e21414
git.kernel.org/stable/c/4f621ae3a2... WEB
https://git.kernel.org/stable/c/4f621ae3a2d99b0bac50e8d66cbf7f68323c01e8
git.kernel.org/stable/c/6b4f48728f... WEB
https://git.kernel.org/stable/c/6b4f48728faa8bb514368f7eacda05565dea8696
git.kernel.org/stable/c/823886a1b0... WEB
https://git.kernel.org/stable/c/823886a1b089b49bcd349bc8bd3417b7910cd1ac
git.kernel.org/stable/c/a8874c34c4... WEB
https://git.kernel.org/stable/c/a8874c34c4a973f9922908a4b8be1d1278f01e42
git.kernel.org/stable/c/dc892cbb1e... WEB
https://git.kernel.org/stable/c/dc892cbb1e4341d427b1f940ebd6abd69bf8e479
git.kernel.org/stable/c/f62a1f245a... WEB
https://git.kernel.org/stable/c/f62a1f245a71680033260a6f6d74011cc3acb3cd

Frequently Asked Questions

What is CVE-2026-72166?
CVE-2026-72166 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-2026-72166?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-72166?
CVE-2026-72166 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-72166?
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-m993-rm7r-56rw",
  "modified" : "2026-08-23T15:33:00Z",
  "published" : "2026-08-15T06:32:14Z",
  "aliases" : [ "CVE-2026-72166" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/9p: fix infinite loop in p9_client_rpc on fatal signal\n\nWhen p9_client_rpc() is called with type P9_TFLUSH and the transport\nhas no peer (e.g. fd transport backed by pipes with no 9p server),\na fatal signal causes an infinite loop:\n\n  again:\n\terr = io_wait_event_killable(req->wq, ...)\n\t/* SIGKILL wakes the task, returns -ERESTARTSYS */\n\n\tif (err == -ERESTARTSYS && c->status == Connected &&\n\t\ttype == P9_TFLUSH) {\n\t\tsigpending = 1;\n\t\tclear_thread_flag(TIF_SIGPENDING);\n\t\tgoto again;\n\t}\n\nclear_thread_flag() clears TIF_SIGPENDING before jumping back to\nio_wait_event_killable(). signal_pending_state() checks TIF_SIGPENDING,\nfinds it zero, and the task goes to sleep again. The task can only wake\non the next signal delivery that calls signal_wake_up() and sets\nTIF_SIGPENDING again. When that happens the loop repeats, clears\nTIF_SIGPENDING, and sleeps again indefinitely.\n\nThis is triggered in practice by coredump_wait(): when a thread in a\nmulti-threaded process causes a coredump (e.g. via SIGSYS from Syscall\nUser Dispatch), coredump_wait() sends SIGKILL to all other threads and\nwaits for them to call mm_release(). If one of those threads is blocked\nin p9_client_rpc() over an fd transport with no peer, it enters the\nP9_TFLUSH loop and never calls mm_release(), so coredump_wait() stalls\nforever:\n\nINFO: task syz.0.18:676 blocked for more than 143 seconds.\n      Not tainted 6.12.77+ #1\ntask:syz.0.18 state:D stack:27600 pid:676 tgid:673 ppid:630 flags:0x00000004\nCall Trace:\n <TASK>\n context_switch kernel/sched/core.c:5344 [inline]\n __schedule+0xcb4/0x5d50 kernel/sched/core.c:6724\n __schedule_loop kernel/sched/core.c:6801 [inline]\n schedule+0xe5/0x350 kernel/sched/core.c:6816\n schedule_timeout+0x253/0x290 kernel/time/timer.c:2593\n do_wait_for_common kernel/sched/completion.c:95 [inline]\n __wait_for_common+0x409/0x600 kernel/sched/completion.c:116\n wait_for_common kernel/sched/completion.c:127 [inline]\n wait_for_completion_state+0x1d/0x40 kernel/sched/completion.c:264\n coredump_wait fs/coredump.c:448 [inline]\n do_coredump+0x854/0x4350 fs/coredump.c:629\n get_signal+0x1425/0x2730 kernel/signal.c:2903\n arch_do_signal_or_restart+0x81/0x880 arch/x86/kernel/signal.c:337\n exit_to_user_mode_loop kernel/entry/common.c:111 [inline]\n exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]\n __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]\n syscall_exit_to_user_mode+0xf9/0x160 kernel/entry/common.c:218\n do_syscall_64+0x102/0x220 arch/x86/entry/common.c:84\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\nFix: check fatal_signal_pending() before clearing TIF_SIGPENDING in the\nP9_TFLUSH retry loop. At that point TIF_SIGPENDING is still set, so\nfatal_signal_pending() works correctly. If a fatal signal is pending,\njump to recalc_sigpending to restore TIF_SIGPENDING and return\n-ERESTARTSYS to the caller.\n\nThe same defect is present in stable kernels back to 5.4. On those\nkernels the infinite loop is broken earlier by a second SIGKILL from\nthe parent process (e.g. kill_and_wait() retrying after a timeout),\nresulting in a zombie process and a shutdown delay rather than a\npermanent D-state hang, but the underlying flaw is the same.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72166"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/18a3427526e2141f80050f82c1d26b19a454707d"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/378481cc60a937ef8ea4ef6e4f95f0dbc4e21414"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/4f621ae3a2d99b0bac50e8d66cbf7f68323c01e8"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/6b4f48728faa8bb514368f7eacda05565dea8696"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/823886a1b089b49bcd349bc8bd3417b7910cd1ac"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/a8874c34c4a973f9922908a4b8be1d1278f01e42"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/dc892cbb1e4341d427b1f940ebd6abd69bf8e479"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/f62a1f245a71680033260a6f6d74011cc3acb3cd"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-15T06:21:34Z"
  }
}