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CVE Record

CVE-2026-64078: netfilter: x_tables: add and use xtables_unregister_table_exit

In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: add and use xtables_unregister_table_exit Previous change added xtables_unregister_table_pre_exit to detach the table from the packetpath and to unlink it from the active table list. In case of rmmod, userspace that is doing set/getsockopt for this table will not be able to re-instantiate the table: 1. The larval table has been removed already 2. existing instantiated table is no longer on the xt pernet table list. This adds the second stage helper: unlink the table from the dying list, free the hook ops (if any) and do the audit notification. It replaces xt_unregister_table().

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a high-severity Linux kernel issue in netfilter x_tables cleanup during module removal. A local low-privileged attacker may be able to trigger serious kernel impact if the affected code path is reachable. The supplied sources show upstream stable fixes, but do not show active exploitation.

Executive priority

Treat as high priority for Linux fleets with local users or untrusted workloads. The risk is not described as internet-exposed remote compromise, but kernel-level impact after local access can materially increase breach severity. Patch through normal emergency kernel update channels once vendor packages are available.

Technical view

The issue concerns x_tables table unregister logic during rmmod and concurrent userspace set/getsockopt activity. The fix adds a second-stage xtables_unregister_table_exit helper to unlink dying tables, free hook ops, and send audit notification, replacing xt_unregister_table(). CVSS is 7.8, local, low complexity, low privileges, no user interaction.

Likely exposure

Linux systems running affected kernel builds with netfilter x_tables support are the relevant exposure. Systems with local users, shared hosting, CI runners, or container workloads deserve priority review. The version data in the bundle is incomplete and should be confirmed against distribution kernel advisories and backports.

Exploitation context

No provided source says this is actively exploited, and the bundle marks CISA KEV as false. The CVSS vector indicates local exploitation requiring low privileges, not remote network-only exploitation. The described condition involves module removal and userspace table operations.

Researcher notes

The source bundle supports a kernel lifecycle bug around x_tables unregister ordering. It does not provide CWE classification, exploit proof, exact affected distribution packages, or a full fixed-version matrix. Validate with kernel commit history and downstream advisories before making product-specific exposure claims.

Mitigation direction

  • Apply a vendor kernel update containing the referenced stable fixes.
  • Check distribution advisories for backported fixes, not only upstream version numbers.
  • Prioritize multi-user, container-host, and untrusted-workload Linux systems.
  • Limit unnecessary local shell access on systems pending kernel updates.
  • Follow vendor guidance if no patched package is available yet.

Validation and detection

  • Inventory Linux kernel versions and distribution package release levels.
  • Confirm whether vendor advisories map CVE-2026-64078 to installed kernels.
  • Check whether netfilter x_tables or iptables modules are present or loaded.
  • Verify patched systems include the referenced upstream stable commits or vendor backports.
  • Record CISA KEV status as not listed based on supplied data.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2026-64078 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-64078Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxfdacd57c79b79a03c7ca88f706ad9fb7b46831c1, fdacd57c79b79a03c7ca88f706ad9fb7b46831c1, fdacd57c79b79a03c7ca88f706ad9fb7b46831c1unaffected
LinuxLinux5.15, 0, 6.18.34, 7.0.11, 7.1affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.