CVE-2026-98642: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-9437-xj9f-2c6g
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Advisory Summary

CVE-2026-98642 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-2026-98642 at a Glance

CVE Identifier CVE-2026-98642
GHSA Identifier GHSA-9437-xj9f-2c6g
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-2026-98642

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-2026-98642, 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: bpf: Fix UAF due to concurrent consumption of ttrace lists in alloc_bulk Syzkaller repeatedly triggered UAF splats related to nodes in waiting_for_gp_ttrace within the bpf memalloc: BUG: KASAN: slab-use-after-free in llist_del_first+0x85/0x110 lib/llist.c:61 Read of size 8 at addr ffff8881572cd080 by task syz.4.470/5112 ... llist_del_first+0x85/0x110 lib/llist.c:61 alloc_bulk+0x193/0x460 kernel/bpf/memalloc.c:229 bpf_mem_refill+0x386/0x560 kernel/bpf/memalloc.c:436 Freed by task 14: ... __free_rcu kernel/bpf/memalloc.c:281 [inline] __free_rcu_tasks_trace+0x48/0xd0 kernel/bpf/memalloc.c:291 rcu_tasks_invoke_cbs+0x1ec/0x3e0 kernel/rcu/tasks.h:571 rcu_tasks_one_gp+0x13d/0x220 kernel/rcu/tasks.h:621 rcu_tasks_kthread+0xf3/0x120 kernel/rcu/tasks.h:651 The reason is that the UAF occurs after the RCU Tasks Trace GP expires: when the __free_rcu() callback runs, there is no synchronization protecting llist_del_all() against concurrent alloc_bulk() operating on waiting_for_gp_ttrace, leading to the race condition below: CPU0 CPU1 __free_rcu (RCU Tasks Trace callback) alloc_bulk llist_del_first(&c->waiting_for_gp_ttrace) entry = smp_load_acquire(&head->first); do { if (entry == NULL) return NULL; free_all(llist_del_all(&c->waiting_for_gp_ttrace)) llist_for_each_safe(pos, t, llnode) free_one(pos); next = READ_ONCE(entry->next); <-- trigger UAF } while (!try_cmpxchg(&head->first, &entry, next)); In addition, there is also a theoretical race condition on the free_by_rcu_ttrace list. This race requires two preconditions: an in-flight Tasks Trace GP keeping c->call_rcu_ttrace_in_progress == 1, and concurrent cross-CPU frees repopulating c->free_by_rcu_ttrace with new nodes. Under these conditions, the following scenario triggers UAF: // CPU0 // irq work is still busy (on PREEMPT_RT) alloc_bulk() llist_del_first(&c->free_by_rcu_ttrace) entry = smp_load_acquire(&head->first); do { if (entry == NULL) return NULL; // CPU1 bpf_mem_alloc_destroy() WRITE_ONCE(c->draining, true) // wait for CPU0 irq_work_sync() // CPU2 do_call_rcu_ttrace(tgt(CPU0)) if (c->draining) { llist_del_all(&c->free_by_rcu_ttrace) free_all() } // CPU0 continue next = READ_ONCE(entry->next); <-- trigger UAF while (!try_cmpxchg(&head->first, &entry, next)); Fix this by introducing a raw spinlock to synchronize the concurrent consumption on waiting_for_gp_ttrace and free_by_rcu_ttrace.

References

NVD — CVE-2026-98642 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-98642
git.kernel.org/stable/c/1c21452d02... WEB
https://git.kernel.org/stable/c/1c21452d02eec2f008e2c5535820f85adbd7587a
git.kernel.org/stable/c/1d6581b544... WEB
https://git.kernel.org/stable/c/1d6581b544a88cf4348c2fb60dcb50ad63f012da
git.kernel.org/stable/c/a0e150a118... WEB
https://git.kernel.org/stable/c/a0e150a118025a05c8662c536ba2a865da86419c
git.kernel.org/stable/c/f101602415... WEB
https://git.kernel.org/stable/c/f101602415fb39a58941bec444df65634d5a6844

Frequently Asked Questions

What is CVE-2026-98642?
CVE-2026-98642 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-2026-98642?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-98642?
CVE-2026-98642 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-98642?
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-9437-xj9f-2c6g",
  "modified" : "2026-10-18T18:31:57Z",
  "published" : "2026-10-18T18:31:57Z",
  "aliases" : [ "CVE-2026-98642" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix UAF due to concurrent consumption of ttrace lists in alloc_bulk\n\nSyzkaller repeatedly triggered UAF splats related to nodes in\nwaiting_for_gp_ttrace within the bpf memalloc:\n\nBUG: KASAN: slab-use-after-free in llist_del_first+0x85/0x110 lib/llist.c:61\nRead of size 8 at addr ffff8881572cd080 by task syz.4.470/5112\n ...\n llist_del_first+0x85/0x110 lib/llist.c:61\n alloc_bulk+0x193/0x460 kernel/bpf/memalloc.c:229\n bpf_mem_refill+0x386/0x560 kernel/bpf/memalloc.c:436\n\nFreed by task 14:\n ...\n __free_rcu kernel/bpf/memalloc.c:281 [inline]\n __free_rcu_tasks_trace+0x48/0xd0 kernel/bpf/memalloc.c:291\n rcu_tasks_invoke_cbs+0x1ec/0x3e0 kernel/rcu/tasks.h:571\n rcu_tasks_one_gp+0x13d/0x220 kernel/rcu/tasks.h:621\n rcu_tasks_kthread+0xf3/0x120 kernel/rcu/tasks.h:651\n\nThe reason is that the UAF occurs after the RCU Tasks Trace GP expires:\nwhen the __free_rcu() callback runs, there is no synchronization\nprotecting llist_del_all() against concurrent alloc_bulk() operating on\nwaiting_for_gp_ttrace, leading to the race condition below:\n\nCPU0                                           CPU1\n                                               __free_rcu (RCU Tasks Trace callback)\nalloc_bulk\n  llist_del_first(&c->waiting_for_gp_ttrace)\n    entry = smp_load_acquire(&head->first);\n    do {\n      if (entry == NULL)\n        return NULL;\n                                               free_all(llist_del_all(&c->waiting_for_gp_ttrace))\n                                                 llist_for_each_safe(pos, t, llnode)\n                                                   free_one(pos);\n      next = READ_ONCE(entry->next); <-- trigger UAF\n    } while (!try_cmpxchg(&head->first, &entry, next));\n\nIn addition, there is also a theoretical race condition on the\nfree_by_rcu_ttrace list. This race requires two preconditions: an\nin-flight Tasks Trace GP keeping c->call_rcu_ttrace_in_progress == 1,\nand concurrent cross-CPU frees repopulating c->free_by_rcu_ttrace with\nnew nodes. Under these conditions, the following scenario triggers UAF:\n\n// CPU0\n// irq work is still busy (on PREEMPT_RT)\nalloc_bulk()\n  llist_del_first(&c->free_by_rcu_ttrace)\n    entry = smp_load_acquire(&head->first);\n    do {\n      if (entry == NULL)\n        return NULL;\n\n        // CPU1\n        bpf_mem_alloc_destroy()\n          WRITE_ONCE(c->draining, true)\n          // wait for CPU0\n          irq_work_sync()\n\n                // CPU2\n                do_call_rcu_ttrace(tgt(CPU0))\n                  if (c->draining) {\n                    llist_del_all(&c->free_by_rcu_ttrace)\n                    free_all()\n                  }\n\n// CPU0 continue\n      next = READ_ONCE(entry->next); <-- trigger UAF\n    while (!try_cmpxchg(&head->first, &entry, next));\n\nFix this by introducing a raw spinlock to synchronize the concurrent\nconsumption on waiting_for_gp_ttrace and free_by_rcu_ttrace.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-98642"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/1c21452d02eec2f008e2c5535820f85adbd7587a"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/1d6581b544a88cf4348c2fb60dcb50ad63f012da"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/a0e150a118025a05c8662c536ba2a865da86419c"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/f101602415fb39a58941bec444df65634d5a6844"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-10-18T16:17:17Z"
  }
}