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Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2026-50260)

high Nessus Plugin ID 314333

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Synopsis

The remote Oracle Linux host is missing one or more security updates.

Description

The remote Oracle Linux 10 / 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-50260 advisory.

 - In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU in ip6_xmit() Use RCU in ip6_xmit() in order to use dst_dev_rcu() to prevent possible UAF. (CVE-2025-40135)

 - This vulnerability was found and addressed by AMD. We are documenting it in the Security Update Guide to encourage customers to install the May 2026 version of Windows as soon as possible. The vulnerability assigned to this CVE is in certain processor models offered by AMD. The mitigation for this vulnerability requires a Windows update. This CVE is being documented in the Security Update Guide to announce that the latest builds of Windows enable the mitigation and provide protection against the vulnerability. Please see the following for more information: AMD-SB-7052 (CVE-2025-54518)

 - 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--- (CVE-2026-23004)

 - In the Linux kernel, the following vulnerability has been resolved: tls: Fix race condition in tls_sw_cancel_work_tx() This issue was discovered during a code audit. After cancel_delayed_work_sync() is called from tls_sk_proto_close(), tx_work_handler() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the tx_work_handler() worker may dereference a freed TLS object.
 The following is a simple race scenario: cpu0 cpu1 tls_sk_proto_close() tls_sw_cancel_work_tx() tls_write_space() tls_sw_write_space() if (!test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask)) set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask); cancel_delayed_work_sync(&ctx->tx_work.work);
 schedule_delayed_work(&tx_ctx->tx_work.work, 0); To prevent this race condition, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync(). (CVE-2026-23240)

 - In the Linux kernel, the following vulnerability has been resolved: RDMA/umad: Reject negative data_len in ib_umad_write ib_umad_write computes data_len from user-controlled count and the MAD header sizes. With a mismatched user MAD header size and RMPP header length, data_len can become negative and reach ib_create_send_mad(). This can make the padding calculation exceed the segment size and trigger an out-of- bounds memset in alloc_send_rmpp_list(). Add an explicit check to reject negative data_len before creating the send buffer. KASAN splat: [ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0 [ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102 [ 211.365867] ib_create_send_mad+0xa01/0x11b0 [ 211.365887] ib_umad_write+0x853/0x1c80 (CVE-2026-23243)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://linux.oracle.com/errata/ELSA-2026-50260.html

Plugin Details

Severity: High

ID: 314333

File Name: oraclelinux_ELSA-2026-50260.nasl

Version: 1.3

Type: Local

Agent: unix

Published: 5/12/2026

Updated: 5/13/2026

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 10.0

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.9

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-43500

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:H/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.6

Threat Score: 8.6

Threat Vector: CVSS:4.0/E:A

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2026-31431

Vulnerability Information

CPE: p-cpe:/a:oracle:linux:kernel-uek64k-modules-extra-netfilter, p-cpe:/a:oracle:linux:kernel-uek-doc, p-cpe:/a:oracle:linux:kernel-uek64k-modules-deprecated, p-cpe:/a:oracle:linux:kernel-uek-modules-core, p-cpe:/a:oracle:linux:kernel-uek-modules-extra, p-cpe:/a:oracle:linux:kernel-uek-modules-wireless, p-cpe:/a:oracle:linux:kernel-uek64k-modules-extra, p-cpe:/a:oracle:linux:kernel-uek-modules, cpe:/o:oracle:linux:9, p-cpe:/a:oracle:linux:kernel-uek-debug, p-cpe:/a:oracle:linux:kernel-uek, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-core, p-cpe:/a:oracle:linux:kernel-uek64k, p-cpe:/a:oracle:linux:kernel-uek64k-modules, p-cpe:/a:oracle:linux:kernel-uek64k-modules-desktop, p-cpe:/a:oracle:linux:kernel-uek-debug-devel, p-cpe:/a:oracle:linux:kernel-uek-modules-deprecated, p-cpe:/a:oracle:linux:kernel-uek-modules-usb, p-cpe:/a:oracle:linux:kernel-uek-devel, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-wireless, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-extra-netfilter, p-cpe:/a:oracle:linux:kernel-uek64k-modules-usb, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-desktop, p-cpe:/a:oracle:linux:kernel-uek-debug-core, p-cpe:/a:oracle:linux:kernel-uek-modules-extra-netfilter, p-cpe:/a:oracle:linux:kernel-uek-tools, p-cpe:/a:oracle:linux:kernel-uek-debug-modules, cpe:/o:oracle:linux:10, p-cpe:/a:oracle:linux:kernel-uek64k-devel, p-cpe:/a:oracle:linux:kernel-uek-modules-desktop, p-cpe:/a:oracle:linux:kernel-uek64k-modules-wireless, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-usb, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-extra, p-cpe:/a:oracle:linux:kernel-uek64k-core, p-cpe:/a:oracle:linux:kernel-uek64k-modules-core, p-cpe:/a:oracle:linux:kernel-uek-core, p-cpe:/a:oracle:linux:kernel-uek-debug-modules-deprecated

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/OracleLinux

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/10/2026

Vulnerability Publication Date: 11/12/2025

CISA Known Exploited Vulnerability Due Dates: 5/15/2026

Exploitable With

Core Impact

Metasploit (Copy Fail AF_ALG + authencesn Page-Cache Write)

Reference Information

CVE: CVE-2025-40135, CVE-2025-54518, CVE-2026-23004, CVE-2026-23240, CVE-2026-23243, CVE-2026-23249, CVE-2026-23250, CVE-2026-23251, CVE-2026-23273, CVE-2026-23443, CVE-2026-31411, CVE-2026-31413, CVE-2026-31431, CVE-2026-43284, CVE-2026-43500

IAVA: 2026-A-0428