Vulnerability-Lookup

FKIE_CVE-2026-23004

Vulnerability from fkie_nvd - Published: 2026-01-25 15:15 - Updated: 2026-04-27 14:16

Severity ?

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list() syzbot was able to crash the kernel in rt6_uncached_list_flush_dev() in an interesting way [1] Crash happens in list_del_init()/INIT_LIST_HEAD() while writing list->prev, while the prior write on list->next went well. static inline void INIT_LIST_HEAD(struct list_head *list) { WRITE_ONCE(list->next, list); // This went well WRITE_ONCE(list->prev, list); // Crash, @list has been freed. } Issue here is that rt6_uncached_list_del() did not attempt to lock ul->lock, as list_empty(&rt->dst.rt_uncached) returned true because the WRITE_ONCE(list->next, list) happened on the other CPU. We might use list_del_init_careful() and list_empty_careful(), or make sure rt6_uncached_list_del() always grabs the spinlock whenever rt->dst.rt_uncached_list has been set. A similar fix is neeed for IPv4. [1] BUG: KASAN: slab-use-after-free in INIT_LIST_HEAD include/linux/list.h:46 [inline] BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:296 [inline] BUG: KASAN: slab-use-after-free in rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline] BUG: KASAN: slab-use-after-free in rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020 Write of size 8 at addr ffff8880294cfa78 by task kworker/u8:14/3450 CPU: 0 UID: 0 PID: 3450 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 INIT_LIST_HEAD include/linux/list.h:46 [inline] list_del_init include/linux/list.h:296 [inline] rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline] rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020 addrconf_ifdown+0x143/0x18a0 net/ipv6/addrconf.c:3853 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] netif_close_many+0x29c/0x410 net/core/dev.c:1785 unregister_netdevice_many_notify+0xb50/0x2330 net/core/dev.c:12353 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 </TASK> Allocated by task 803: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270 dst_alloc+0x105/0x170 net/core/dst.c:89 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333 mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entr ---truncated---

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/722de945216144af7cd4d39bdeb936108d2595a7	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/815db2363e51f0ef416947492d4dac5b7a520f56	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9a6f0c4d5796ab89b5a28a890ce542344d58bd69	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f24a52948c95e02facbca2b3b6eb5a225e27eb01	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	3.6
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19

JSON

To clipboard

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  "cveTags": [],
  "descriptions": [
    {
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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()\n\nsyzbot was able to crash the kernel in rt6_uncached_list_flush_dev()\nin an interesting way [1]\n\nCrash happens in list_del_init()/INIT_LIST_HEAD() while writing\nlist-\u003eprev, while the prior write on list-\u003enext went well.\n\nstatic inline void INIT_LIST_HEAD(struct list_head *list)\n{\n\tWRITE_ONCE(list-\u003enext, list); // This went well\n\tWRITE_ONCE(list-\u003eprev, list); // Crash, @list has been freed.\n}\n\nIssue here is that rt6_uncached_list_del() did not attempt to lock\nul-\u003elock, as list_empty(\u0026rt-\u003edst.rt_uncached) returned\ntrue because the WRITE_ONCE(list-\u003enext, list) happened on the other CPU.\n\nWe might use list_del_init_careful() and list_empty_careful(),\nor make sure rt6_uncached_list_del() always grabs the spinlock\nwhenever rt-\u003edst.rt_uncached_list has been set.\n\nA similar fix is neeed for IPv4.\n\n[1]\n\n BUG: KASAN: slab-use-after-free in INIT_LIST_HEAD include/linux/list.h:46 [inline]\n BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:296 [inline]\n BUG: KASAN: slab-use-after-free in rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]\n BUG: KASAN: slab-use-after-free in rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020\nWrite of size 8 at addr ffff8880294cfa78 by task kworker/u8:14/3450\n\nCPU: 0 UID: 0 PID: 3450 Comm: kworker/u8:14 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)}\nTainted: [L]=SOFTLOCKUP\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025\nWorkqueue: netns cleanup_net\nCall Trace:\n \u003cTASK\u003e\n  dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n  print_address_description mm/kasan/report.c:378 [inline]\n  print_report+0xca/0x240 mm/kasan/report.c:482\n  kasan_report+0x118/0x150 mm/kasan/report.c:595\n  INIT_LIST_HEAD include/linux/list.h:46 [inline]\n  list_del_init include/linux/list.h:296 [inline]\n  rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]\n  rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020\n  addrconf_ifdown+0x143/0x18a0 net/ipv6/addrconf.c:3853\n addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1\n  notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85\n  call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]\n  call_netdevice_notifiers net/core/dev.c:2282 [inline]\n  netif_close_many+0x29c/0x410 net/core/dev.c:1785\n  unregister_netdevice_many_notify+0xb50/0x2330 net/core/dev.c:12353\n  ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]\n  ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248\n  cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696\n  process_one_work kernel/workqueue.c:3257 [inline]\n  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340\n  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421\n  kthread+0x711/0x8a0 kernel/kthread.c:463\n  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158\n  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246\n \u003c/TASK\u003e\n\nAllocated by task 803:\n  kasan_save_stack mm/kasan/common.c:57 [inline]\n  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n  unpoison_slab_object mm/kasan/common.c:340 [inline]\n  __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366\n  kasan_slab_alloc include/linux/kasan.h:253 [inline]\n  slab_post_alloc_hook mm/slub.c:4953 [inline]\n  slab_alloc_node mm/slub.c:5263 [inline]\n  kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270\n  dst_alloc+0x105/0x170 net/core/dst.c:89\n  ip6_dst_alloc net/ipv6/route.c:342 [inline]\n  icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333\n  mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844\n  mld_send_cr net/ipv6/mcast.c:2154 [inline]\n  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693\n  process_one_work kernel/workqueue.c:3257 [inline]\n  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340\n  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421\n  kthread+0x711/0x8a0 kernel/kthread.c:463\n  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158\n  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entr\n---truncated---"
    }
  ],
  "id": "CVE-2026-23004",
  "lastModified": "2026-04-27T14:16:29.243",
  "metrics": {
    "cvssMetricV31": [
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        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
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          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "exploitabilityScore": 1.0,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
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  "published": "2026-01-25T15:15:55.273",
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}

CVE-2026-23004 (GCVE-0-2026-23004)

Vulnerability from cvelistv5 – Published: 2026-01-25 14:36 – Updated: 2026-04-27 14:02

Title

dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()

Summary

Severity ?

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/815db2363e51f0ef4…
	https://git.kernel.org/stable/c/f24a52948c95e02fa…
	https://git.kernel.org/stable/c/722de945216144af7…
	https://git.kernel.org/stable/c/9a6f0c4d5796ab89b…

Impacted products

Vendor

Product

Version

Linux

Affected: 78df76a065ae3b5dbcb9a29912adc02f697de498 , < 815db2363e51f0ef416947492d4dac5b7a520f56 (git)
Affected: 78df76a065ae3b5dbcb9a29912adc02f697de498 , < f24a52948c95e02facbca2b3b6eb5a225e27eb01 (git)
Affected: 78df76a065ae3b5dbcb9a29912adc02f697de498 , < 722de945216144af7cd4d39bdeb936108d2595a7 (git)
Affected: 78df76a065ae3b5dbcb9a29912adc02f697de498 , < 9a6f0c4d5796ab89b5a28a890ce542344d58bd69 (git)

Linux

Affected: 3.6
Unaffected: 0 , < 3.6 (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.7 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.7",
                  "versionStartIncluding": "3.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "3.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()\n\nsyzbot was able to crash the kernel in rt6_uncached_list_flush_dev()\nin an interesting way [1]\n\nCrash happens in list_del_init()/INIT_LIST_HEAD() while writing\nlist-\u003eprev, while the prior write on list-\u003enext went well.\n\nstatic inline void INIT_LIST_HEAD(struct list_head *list)\n{\n\tWRITE_ONCE(list-\u003enext, list); // This went well\n\tWRITE_ONCE(list-\u003eprev, list); // Crash, @list has been freed.\n}\n\nIssue here is that rt6_uncached_list_del() did not attempt to lock\nul-\u003elock, as list_empty(\u0026rt-\u003edst.rt_uncached) returned\ntrue because the WRITE_ONCE(list-\u003enext, list) happened on the other CPU.\n\nWe might use list_del_init_careful() and list_empty_careful(),\nor make sure rt6_uncached_list_del() always grabs the spinlock\nwhenever rt-\u003edst.rt_uncached_list has been set.\n\nA similar fix is neeed for IPv4.\n\n[1]\n\n BUG: KASAN: slab-use-after-free in INIT_LIST_HEAD include/linux/list.h:46 [inline]\n BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:296 [inline]\n BUG: KASAN: slab-use-after-free in rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]\n BUG: KASAN: slab-use-after-free in rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020\nWrite of size 8 at addr ffff8880294cfa78 by task kworker/u8:14/3450\n\nCPU: 0 UID: 0 PID: 3450 Comm: kworker/u8:14 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)}\nTainted: [L]=SOFTLOCKUP\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025\nWorkqueue: netns cleanup_net\nCall Trace:\n \u003cTASK\u003e\n  dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n  print_address_description mm/kasan/report.c:378 [inline]\n  print_report+0xca/0x240 mm/kasan/report.c:482\n  kasan_report+0x118/0x150 mm/kasan/report.c:595\n  INIT_LIST_HEAD include/linux/list.h:46 [inline]\n  list_del_init include/linux/list.h:296 [inline]\n  rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]\n  rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020\n  addrconf_ifdown+0x143/0x18a0 net/ipv6/addrconf.c:3853\n addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1\n  notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85\n  call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]\n  call_netdevice_notifiers net/core/dev.c:2282 [inline]\n  netif_close_many+0x29c/0x410 net/core/dev.c:1785\n  unregister_netdevice_many_notify+0xb50/0x2330 net/core/dev.c:12353\n  ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]\n  ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248\n  cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696\n  process_one_work kernel/workqueue.c:3257 [inline]\n  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340\n  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421\n  kthread+0x711/0x8a0 kernel/kthread.c:463\n  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158\n  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246\n \u003c/TASK\u003e\n\nAllocated by task 803:\n  kasan_save_stack mm/kasan/common.c:57 [inline]\n  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78\n  unpoison_slab_object mm/kasan/common.c:340 [inline]\n  __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366\n  kasan_slab_alloc include/linux/kasan.h:253 [inline]\n  slab_post_alloc_hook mm/slub.c:4953 [inline]\n  slab_alloc_node mm/slub.c:5263 [inline]\n  kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270\n  dst_alloc+0x105/0x170 net/core/dst.c:89\n  ip6_dst_alloc net/ipv6/route.c:342 [inline]\n  icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333\n  mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844\n  mld_send_cr net/ipv6/mcast.c:2154 [inline]\n  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693\n  process_one_work kernel/workqueue.c:3257 [inline]\n  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340\n  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421\n  kthread+0x711/0x8a0 kernel/kthread.c:463\n  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158\n  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entr\n---truncated---"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-27T14:02:07.671Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/815db2363e51f0ef416947492d4dac5b7a520f56"
        },
        {
          "url": "https://git.kernel.org/stable/c/f24a52948c95e02facbca2b3b6eb5a225e27eb01"
        },
        {
          "url": "https://git.kernel.org/stable/c/722de945216144af7cd4d39bdeb936108d2595a7"
        },
        {
          "url": "https://git.kernel.org/stable/c/9a6f0c4d5796ab89b5a28a890ce542344d58bd69"
        }
      ],
      "title": "dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23004",
    "datePublished": "2026-01-25T14:36:18.233Z",
    "dateReserved": "2026-01-13T15:37:45.939Z",
    "dateUpdated": "2026-04-27T14:02:07.671Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-23004

CVE-2026-23004 (GCVE-0-2026-23004)

Tags

Sightings

Nomenclature