CVE-2026-98021Public exploit

System memory exhaustion via oversized transmit queues

Published Sep 25, 2026 · Updated Sep 25, 2026

Resource exhaustion in Linux 2.6.23 and later allows local users to exhaust system memory through oversized transmit queues. rtnl_create_link() assigns an unbounded IFLA_TXQLEN value directly to dev->tx_queue_len, allowing pfifo_fast and related ring allocations to scale from attacker-controlled input. Exploitation requires network scheduling, veth, user namespaces, and network namespaces; an unprivileged local user can cause system-wide memory pressure from a fresh namespace.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Linux 2.6.23 and later allows local users to exhaust system memory through oversized transmit queues. rtnl_create_link() assigns an unbounded IFLA_TXQLEN value directly to dev->tx_queue_len, allowing pfifo_fast and related ring allocations to scale from attacker-controlled input. Exploitation requires network scheduling, veth, user namespaces, and network namespaces; an unprivileged local user can cause system-wide memory pressure from a fresh namespace.

The record

CVE
CVE-2026-98021
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.23
  2. Affected versionversion=38f7b870d4a6a5d3ec21557e849620cb7d032965 <1aa9e143bf51405665a793d4cc925e1c4f0c5922
  3. Affected versionversion=38f7b870d4a6a5d3ec21557e849620cb7d032965 <2fd0880f0272ec022906a05587fd91416ebecc38
  4. Affected versionversion=38f7b870d4a6a5d3ec21557e849620cb7d032965 <45ca9f59b6c7ea70e0a17054902b8a556913db34
  5. Affected versionversion=38f7b870d4a6a5d3ec21557e849620cb7d032965 <a638a2625aa83160a394abe8e8b2e524a80c771b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.23; version=38f7b870d4a6a5d3ec21557e849620cb7d032965 <1aa9e143bf51405665a793d4cc925e1c4f0c5922; version=38f7b870d4a6a5d3ec21557e849620cb7d032965 <2fd0880f0272ec022906a05587fd91416ebecc38; version=38f7b870d4a6a5d3ec21557e849620cb7d032965 <45ca9f59b6c7ea70e0a17054902b8a556913db34; version=38f7b870d4a6a5d3ec21557e849620cb7d032965 <a638a2625aa83160a394abe8e8b2e524a80c771b

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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