NVD / CVE Program· CNA Linux

CVE-2026-80986: net/smc: bound the peer rkey counts in SMC-Rv2 LLC messages

Noroxi assessment

Priority: Monitor (action score 39/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.64% (FIRST EPSS); higher than 51.3% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 2d1e7c5aaa3326e95e2058457f172ca99a9a4577, 486c699a8cde82c1d9b4f443eeab4ddf86358cb0, 5e5d9e6df677d30a2203d257b5fd8b99814fa607.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2d1e7c5aaa3326e95e2058457f172ca99a9a4577, 486c699a8cde82c1d9b4f443eeab4ddf86358cb0, 5e5d9e6df677d30a2203d257b5fd8b99814fa607 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: net/smc: bound the peer rkey counts in SMC-Rv2 LLC messages On a link whose device has max_recv_sge == 1 there is no shared v2 receive buffer, and smc_llc_save_add_link_rkeys() takes the v2 extension from 44 bytes past the start of the queue entry's inline message: ext = (struct smc_llc_msg_add_link_v2_ext *)(llc_msg + SMC_WR_TX_SIZE); The entry is a 72-byte allocation and the extension starts at offset 68, so ext->num_rkeys at offset 94 is already past it. This happens on every SMC-Rv2 link addition, whatever the peer sends: [ 2.490065] BUG: KASAN: slab-out-of-bounds in smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490431] Read of size 2 at addr ffff8880056406de by task smctest/106 [ 2.490709] [ 2.490792] CPU: 0 UID: 0 PID: 106 Comm: smctest Not tainted 7.2.0-rc5-p1-g77a5d9d9c99f #32 PREEMPT(lazy) [ 2.490795] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 2.490798] Call Trace: [ 2.490803] <TASK> [ 2.490805] dump_stack_lvl+0x53/0x70 [ 2.490810] print_report+0xd0/0x630 [ 2.490828] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 2.490832] ? smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490834] kasan_report+0xce/0x100 [ 2.490836] ? smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490837] smc_llc_save_add_link_rkeys+0x333/0x350 [ 2.490839] ? smcr_buf_map_lgr+0x1bf/0x2b0 [ 2.490844] smc_llc_cli_add_link+0xca7/0x1e80 [ 2.490848] ? smc_llc_wait+0x355/0x810 [ 2.490850] ? __pfx_smc_llc_wait+0x10/0x10 [ 2.490851] ? __pfx_smc_llc_cli_add_link+0x10/0x10 [ 2.490853] ? __pfx_autoremove_wake_function+0x10/0x10 [ 2.490863] __smc_connect+0x3f5c/0x4980 [ 2.490873] ? __pfx_kernel_connect+0x10/0x10 [ 2.490888] ? __pfx___smc_connect+0x10/0x10 [ 2.490891] ? release_sock+0x148/0x1d0 [ 2.490894] smc_connect+0x42c/0x580 [ 2.490896] __sys_connect+0xfc/0x130 [ 2.490898] ? __pfx___sys_connect+0x10/0x10 [ 2.490900] ? handle_mm_fault+0x1a1/0x430 [ 2.490908] __x64_sys_connect+0x6d/0xb0 [ 2.490909] ? fpregs_assert_state_consistent+0x56/0xe0 [ 2.490917] do_syscall_64+0xf9/0x540 [ 2.490921] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 2.490924] RIP: 0033:0x421bb4 [ 2.490927] Code: ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d ad 34 09 00 00 74 13 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 55 [ 2.490929] RSP: 002b:00007ffd473b01a8 EFLAGS: 00000202 ORIG_RAX: 000000000000002a [ 2.490935] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000421bb4 [ 2.490936] RDX: 0000000000000010 RSI: 00007ffd473b01d0 RDI: 0000000000000003 [ 2.490937] RBP: 0000000000003930 R08: 0000000000000004 R09: 0000000000000000 [ 2.490938] R10: 00007ffd473b0f98 R11: 0000000000000202 R12: 0000000000000006 [ 2.490939] R13: 00007ffd473b0f87 R14: 0000000000000003 R15: 00007ffd473b0f90 [ 2.490940] </TASK> [ 2.490941] [ 2.499545] Allocated by task 44: [ 2.499693] kasan_save_stack+0x33/0x60 [ 2.499860] kasan_save_track+0x14/0x30 [ 2.500026] __kasan_kmalloc+0x8f/0xa0 [ 2.500190] __kmalloc_cache_noprof+0x158/0x370 [ 2.500393] smc_llc_enqueue+0x72/0x560 [ 2.500559] smc_wr_rx_tasklet_fn+0x474/0xa80 [ 2.500747] tasklet_action_common+0x20f/0x8a0 [ 2.500945] handle_softirqs+0x18e/0x590 [ 2.501115] do_softirq+0x3b/0x60 [ 2.501266] __local_bh_enable_ip+0x61/0x70 [ 2.501446] __alloc_skb+0x732/0x890 [ 2.501604] rxe_init_packet+0x16b/0x4f0 [ 2.501783] prepare_ack_packet+0xb8/0x830 [ 2.501962] rxe_receiver+0x495/0x96e0 [ 2.502125] do_work+0x144/0x470 [ 2.502269] process_one_work+0x633/0x1030 [ 2.502450] worker_thread+0x45b/0xd10 [ 2.50261 ---truncated---

CriticalCVSS 9.8 · v3.1—No exploit Fix available

Pre-auth

EUVD-2026-76309

Published: Sep 11, 2026
Updated: Oct 19, 2026
EPSS: 0.6% · 51th percentile
CWE: —

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CNA vs NVD score

NVD: —
CNA · Linux: 9.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 6.14affected
- 27ef6a9981fe74191849966a6d5e0400a4008ab8 and later · before 486c699a8cde82c1d9b4f443eeab4ddf86358cb0affected · git
- 27ef6a9981fe74191849966a6d5e0400a4008ab8 and later · before 5e5d9e6df677d30a2203d257b5fd8b99814fa607affected · git
- 27ef6a9981fe74191849966a6d5e0400a4008ab8 and later · before 2d1e7c5aaa3326e95e2058457f172ca99a9a4577affected · git
- before 6.14not affected · semver
- 6.18.50 and later · up to and including 6.18.*not affected · semver
- 7.2.4 and later · up to and including 7.2.*not affected · semver
- 7.3 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:14	linux	before 7.2.6-1	7.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
40Plan
CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
40Plan
CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
40Plan

Published before and after this one in the same product

← EarlierCVE-2026-80984Sep 11, 2026 · net/smc: do not dereference an unset send buffer on the SMC-D teardown path
0Monitor
← EarlierCVE-2026-80985Sep 11, 2026 · net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry
32Monitor
Later →CVE-2026-80987Sep 11, 2026 · NTB: ntb_transport: Reject oversized TX buffers
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	2d1e7c5aaa3326e95e2058457f172ca99a9a4577	Vendor (CNA)
Linux Linux	486c699a8cde82c1d9b4f443eeab4ddf86358cb0	Vendor (CNA)
Linux Linux	5e5d9e6df677d30a2203d257b5fd8b99814fa607	Vendor (CNA)
debian:linux	7.2.6-1 · Debian:14	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-1085 · Sep 14, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/2d1e7c5aaa3326e95e2058457f172ca99a9a4577

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records