CVE-2026-23173 | net/mlx5e: TC, delete flows only for existing peers

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: TC, delete flows only for existing peers When deleting TC steering flows, iterate only over actual devcom peers instead of assuming all possible ports exist. This avoids touching non-existent peers and ensures cleanup is limited to devices the driver is currently connected to. BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 133c8a067 P4D 0 Oops: Oops: 0002 [#1] SMP CPU: 19 UID: 0 PID: 2169 Comm: tc Not tainted 6.18.0+ #156 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:mlx5e_tc_del_fdb_peers_flow+0xbe/0x200 [mlx5_core] Code: 00 00 a8 08 74 a8 49 8b 46 18 f6 c4 02 74 9f 4c 8d bf a0 12 00 00 4c 89 ff e8 0e e7 96 e1 49 8b 44 24 08 49 8b 0c 24 4c 89 ff <48> 89 41 08 48 89 08 49 89 2c 24 49 89 5c 24 08 e8 7d ce 96 e1 49 RSP: 0018:ff11000143867528 EFLAGS: 00010246 RAX: 0000000000000000 RBX: dead000000000122 RCX: 0000000000000000 RDX: ff11000143691580 RSI: ff110001026e5000 RDI: ff11000106f3d2a0 RBP: dead000000000100 R08: 00000000000003fd R09: 0000000000000002 R10: ff11000101c75690 R11: ff1100085faea178 R12: ff11000115f0ae78 R13: 0000000000000000 R14: ff11000115f0a800 R15: ff11000106f3d2a0 FS: 00007f35236bf740(0000) GS:ff110008dc809000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000157a01001 CR4: 0000000000373eb0 Call Trace: <TASK> mlx5e_tc_del_flow+0x46/0x270 [mlx5_core] mlx5e_flow_put+0x25/0x50 [mlx5_core] mlx5e_delete_flower+0x2a6/0x3e0 [mlx5_core] tc_setup_cb_reoffload+0x20/0x80 fl_reoffload+0x26f/0x2f0 [cls_flower] ? mlx5e_tc_reoffload_flows_work+0xc0/0xc0 [mlx5_core] ? mlx5e_tc_reoffload_flows_work+0xc0/0xc0 [mlx5_core] tcf_block_playback_offloads+0x9e/0x1c0 tcf_block_unbind+0x7b/0xd0 tcf_block_setup+0x186/0x1d0 tcf_block_offload_cmd.isra.0+0xef/0x130 tcf_block_offload_unbind+0x43/0x70 __tcf_block_put+0x85/0x160 ingress_destroy+0x32/0x110 [sch_ingress] __qdisc_destroy+0x44/0x100 qdisc_graft+0x22b/0x610 tc_get_qdisc+0x183/0x4d0 rtnetlink_rcv_msg+0x2d7/0x3d0 ? rtnl_calcit.isra.0+0x100/0x100 netlink_rcv_skb+0x53/0x100 netlink_unicast+0x249/0x320 ? __alloc_skb+0x102/0x1f0 netlink_sendmsg+0x1e3/0x420 __sock_sendmsg+0x38/0x60 ____sys_sendmsg+0x1ef/0x230 ? copy_msghdr_from_user+0x6c/0xa0 ___sys_sendmsg+0x7f/0xc0 ? ___sys_recvmsg+0x8a/0xc0 ? __sys_sendto+0x119/0x180 __sys_sendmsg+0x61/0xb0 do_syscall_64+0x55/0x640 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f35238bb764 Code: 15 b9 86 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bf 0f 1f 44 00 00 f3 0f 1e fa 80 3d e5 08 0d 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 20 89 55 RSP: 002b:00007ffed4c35638 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000055a2efcc75e0 RCX: 00007f35238bb764 RDX: 0000000000000000 RSI: 00007ffed4c356a0 RDI: 0000000000000003 RBP: 00007ffed4c35710 R08: 0000000000000010 R09: 00007f3523984b20 R10: 0000000000000004 R11: 0000000000000202 R12: 00007ffed4c35790 R13: 000000006947df8f R14: 000055a2efcc75e0 R15: 00007ffed4c35780

Published: 2026-02-14 Last update: 2026-03-18 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23173 is rated Low Risk (22.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.11%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23173

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.11% +0.10%
2 2026-02-15 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23173

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-23173

OS Trackers for CVE-2026-23173

vendor priority summary link
debian unimportant CVE-2026-23173 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-23173
redhat medium — https://access.redhat.com/security/cve/CVE-2026-23173
suse medium CVE-2026-23173 severity moderate: SUSE including 414 source package names (2.1.3-6.124:kernel-default-base-6.4.0-40.1.21.17, 2.1.3-7.105:kernel-default-6.4.0-40.1, …), 701 product×package rows across 57 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (57 product lines)): Fixed 308, Known Affected 231, Known Not Affected 137, First Fixed 25. https://www.suse.com/security/cve/CVE-2026-23173/
ubuntu medium CVE-2026-23173 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1256 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): DNE 871, ignored 169, released 83, not-affected 79, needed 49, pending 5. https://ubuntu.com/security/CVE-2026-23173

Affected software / configurations for CVE-2026-23173

Vendor Product Version Raw CPE
linux linux_kernel >= 6.5, < 6.6.123 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.69 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.18.9 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*
linux linux_kernel 6.19 cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:*

References for CVE-2026-23173

cvelogic Threat Intelligence