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NVD / CVE Program· CNA Linux

CVE-2026-64004: net/iucv: fix locking in .getsockopt

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.10% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 1fc30bd4e55e2dd622d2d366cecd732c1841bbee, 3589d20a666caf30ad100c960a2de7de390fce88, 45bb8de8c95d8899f4b8f61bd9bceb8132af73cb.

Low priority for now. Upgrade to Linux Linux 1fc30bd4e55e2dd622d2d366cecd732c1841bbee, 3589d20a666caf30ad100c960a2de7de390fce88, 45bb8de8c95d8899f4b8f61bd9bceb8132af73cb 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/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 0th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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.

Get told when this record changes

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-64004

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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 kernel3.4 and later · before 5.10.259
  • linux linux kernel5.11 and later · before 5.15.210
  • linux linux kernel5.16 and later · before 6.1.176
  • linux linux kernel6.2 and later · before 6.6.143
  • linux linux kernel6.7 and later · before 6.12.93
  • linux linux kernel6.13 and later · before 6.18.35
  • linux linux kernel6.19 and later · before 7.0.12
  • 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

    • 3.4affected
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 884eb247b74d86db97e3a37f0d6fc8e1e83590ddaffected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 45bb8de8c95d8899f4b8f61bd9bceb8132af73cbaffected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 1fc30bd4e55e2dd622d2d366cecd732c1841bbeeaffected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before cd691beafea0dd779e69e81ccc26b0ab50efcb5eaffected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 6e792b8dd3002bbc4136745928a9605df1a72b8aaffected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 9817369243380e287ebe5525411557eaa3aa2a79affected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 69554adc7a6fa04ede3ad7512321d83748e3c920affected · git
    • 51363b8751a673a00ad48eea895266396d53fa52 and later · before 3589d20a666caf30ad100c960a2de7de390fce88affected · git
    • before 3.4not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.12-17.0.12-1

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-2026-64002Jul 19, 2026 · ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table()
    31Monitor
  • ← EarlierCVE-2026-64003Jul 19, 2026 · scsi: core: Run queues for all non-SDEV_DEL devices from scsi_run_host_queues
    30Monitor
  • Later →CVE-2026-64005Jul 19, 2026 · net/smc: Do not re-initialize smc hashtables
    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 Linux1fc30bd4e55e2dd622d2d366cecd732c1841bbeeVendor (CNA)
Linux Linux3589d20a666caf30ad100c960a2de7de390fce88Vendor (CNA)
Linux Linux45bb8de8c95d8899f4b8f61bd9bceb8132af73cbVendor (CNA)
Linux Linux69554adc7a6fa04ede3ad7512321d83748e3c920Vendor (CNA)
Linux Linux6e792b8dd3002bbc4136745928a9605df1a72b8aVendor (CNA)
Linux Linux884eb247b74d86db97e3a37f0d6fc8e1e83590ddVendor (CNA)
Linux Linux9817369243380e287ebe5525411557eaa3aa2a79Vendor (CNA)
Linux Linuxcd691beafea0dd779e69e81ccc26b0ab50efcb5eVendor (CNA)
debian:linux6.1.176-1 · Debian:12Package 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).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • 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
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-667 · Improper Locking

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/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.

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