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NVD / CVE Program· CNA Linux

CVE-2026-64048: net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 0.50% (FIRST EPSS).
  • 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 277740023def559a4a2ddc3e8e784ee37a0f16a9, 53eb7bd09aace72fa17510d80e0caf5ca058c231, 65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e.

Low priority for now. Upgrade to Linux Linux 277740023def559a4a2ddc3e8e784ee37a0f16a9, 53eb7bd09aace72fa17510d80e0caf5ca058c231, 65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e 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: reject CHID-0 ACCEPT that matches an empty ism_dev slot On the SMC-D client, slot 0 of ini->ism_dev[]/ini->ism_chid[] is reserved for an SMC-Dv1 device. smc_find_ism_v2_device_clnt() populates V2 entries starting at index 1, so when no V1 device is selected slot 0 is left in its kzalloc()'ed state with ism_dev[0] == NULL and ism_chid[0] == 0. smc_v2_determine_accepted_chid() then matches the peer's CHID against the array starting from index 0 using the CHID alone. A malicious peer replying to a SMC-Dv2-only proposal with d1.chid == 0 matches the empty slot, ini->ism_selected becomes 0, and the subsequent ism_dev[0]->lgr_lock dereference in smc_conn_create() faults at offsetof(struct smcd_dev, lgr_lock) == 0x68: BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x79/0xe0 Write of size 4 at addr 0000000000000068 by task exploit/144 Call Trace: _raw_spin_lock_bh smc_conn_create (net/smc/smc_core.c:1997) __smc_connect (net/smc/af_smc.c:1447) smc_connect (net/smc/af_smc.c:1720) __sys_connect __x64_sys_connect do_syscall_64 Require ism_dev[i] to be non-NULL before accepting a CHID match.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Oct 19, 2026
EPSS
0.5% · 42th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.5
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?

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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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.10 and later · before 5.10.266
  • linux linux kernel5.11 and later · before 5.15.217
  • linux linux kernel5.16 and later · before 6.1.175
  • linux linux kernel6.2 and later · before 6.6.142
  • linux linux kernel6.7 and later · before 6.12.92
  • linux linux kernel6.13 and later · before 6.18.34
  • linux linux kernel6.19 and later · before 7.0.11
  • linux linux kernel7.1

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

    • 5.10affected
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before 903f7688ffeb9b323d70652c01f554bd4ba2a3d6affected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0affected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before 6927cacf2b10d4fa80c1a2d407512ef9397c59c6affected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0affected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before 53eb7bd09aace72fa17510d80e0caf5ca058c231affected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before afa9036b8c9963947b487c36e332df6a42c96fcbaffected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before 65edb3b0822cfe5041be8fbabebd57e2e5ad9f4eaffected · git
    • a7c9c5f4af7f6098da68705fc5d86565d0728ef7 and later · before 277740023def559a4a2ddc3e8e784ee37a0f16a9affected · git
    • before 5.10not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.68.1.el10_26.12.0-211.68.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64046Jul 19, 2026 · net: tls: prevent chain-after-chain in plain text SG
    39Monitor
  • ← EarlierCVE-2026-64047Jul 19, 2026 · net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring
    39Monitor
  • Later →CVE-2026-64053Jul 19, 2026 · block: don't overwrite bip_vcnt in bio_integrity_copy_user()
    31Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
Linux Linux277740023def559a4a2ddc3e8e784ee37a0f16a9Vendor (CNA)
Linux Linux53eb7bd09aace72fa17510d80e0caf5ca058c231Vendor (CNA)
Linux Linux65edb3b0822cfe5041be8fbabebd57e2e5ad9f4eVendor (CNA)
Linux Linux6927cacf2b10d4fa80c1a2d407512ef9397c59c6Vendor (CNA)
Linux Linux903f7688ffeb9b323d70652c01f554bd4ba2a3d6Vendor (CNA)
Linux Linuxafa9036b8c9963947b487c36e332df6a42c96fcbVendor (CNA)
Linux Linuxd38ba387244e5c5f7db3e11ea98bc2c7beccb0c0Vendor (CNA)
Linux Linuxdd2f9dd83c68abd7ba7ded7075290b016cb7ecd0Vendor (CNA)
almalinux:kernel5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.41.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-687.41.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

+5

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).

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records