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CVE Record

CVE-2026-23278: netfilter: nf_tables: always walk all pending catchall elements

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: always walk all pending catchall elements During transaction processing we might have more than one catchall element: 1 live catchall element and 1 pending element that is coming as part of the new batch. If the map holding the catchall elements is also going away, its required to toggle all catchall elements and not just the first viable candidate. Otherwise, we get: WARNING: ./include/net/netfilter/nf_tables.h:1281 at nft_data_release+0xb7/0xe0 [nf_tables], CPU#2: nft/1404 RIP: 0010:nft_data_release+0xb7/0xe0 [nf_tables] [..] __nft_set_elem_destroy+0x106/0x380 [nf_tables] nf_tables_abort_release+0x348/0x8d0 [nf_tables] nf_tables_abort+0xcf2/0x3ac0 [nf_tables] nfnetlink_rcv_batch+0x9c9/0x20e0 [..]

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-23278 is a high-severity Linux kernel netfilter/nf_tables flaw. A local low-privileged user may be able to trigger unsafe kernel transaction cleanup behavior. The source bundle rates impact to confidentiality, integrity, and availability as high, but does not show active exploitation.

Executive priority

Treat as a priority Linux kernel patching issue, especially on shared infrastructure. It is not described as remotely exploitable, but local kernel bugs can materially affect tenant isolation and host integrity.

Technical view

The bug is in nf_tables catchall element handling during transaction abort/release. When a map containing catchall elements is removed, the kernel must process all pending catchall elements, not only the first viable one. The provided trace shows failure in nft_data_release during nf_tables abort cleanup.

Likely exposure

Exposure is likely on Linux systems running affected kernel builds with nf_tables/netfilter present. Risk is most relevant for multi-user servers, container hosts, and systems granting local accounts or workloads.

Exploitation context

The CVSS vector is local, low complexity, low privileges, and no user interaction. KEV is false in the bundle, and no cited source states active exploitation or public exploit availability.

Researcher notes

The bundle provides kernel commit references and a crash trace, but not exploit mechanics, CWE classification, or distribution-specific fix versions. Avoid assuming affected distro packages without vendor confirmation.

Mitigation direction

  • Inventory Linux kernel versions across servers and container hosts.
  • Apply vendor kernel updates that include the referenced upstream stable fixes.
  • Prioritize systems with untrusted local users or hosted workloads.
  • Check distribution advisories for backported fixes and package names.
  • Reduce unnecessary local access until patched where feasible.

Validation and detection

  • Confirm running kernel versions against vendor advisories or fixed package metadata.
  • Verify whether nf_tables/netfilter is enabled or used on exposed systems.
  • Check patch status for the referenced stable kernel commits.
  • Review vulnerability scanner results for CVE-2026-23278 after updates.
  • Track vendor guidance if the installed kernel uses backported fixes.
Prepared
Confidence
medium
Sources
8

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-2026-23278 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
7Source 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-2026-23278Attack 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
LinuxLinuxd60be2da67d172aecf866302c91ea11533eca4d9, 628bd3e49cba1c066228e23d71a852c23e26da73, 628bd3e49cba1c066228e23d71a852c23e26da73, 628bd3e49cba1c066228e23d71a852c23e26da73, 628bd3e49cba1c066228e23d71a852c23e26da73, 628bd3e49cba1c066228e23d71a852c23e26da73, bc9f791d2593f17e39f87c6e2b3a36549a3705b1, 3c7ec098e3b588434a8b07ea9b5b36f04cef1f50, a136b7942ad2a50de708f76ea299ccb45ac7a7f9, 25aa2ad37c2162be1c0bc4fe6397f7e4c13f00f8, dc7cdf8cbcbf8b13de1df93f356ec04cdeef5c41, 6.1.36, 4.19.316, 5.4.262, 5.10.188, 5.15.121, 6.3.10unaffected
LinuxLinux6.4, 0, 6.1.177, 6.6.144, 6.12.78, 6.18.19, 6.19.9, 7.0affected
Weakness

CWE details

No CWE listed

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