CVE-2026-74735

Local service interruption via leaked L2TP references

Published Aug 26, 2026 · Updated Aug 26, 2026

Reference-count leakage in Linux L2TP 4.17 and affected backports allows local users to exhaust resources through partial reads. The pppol2tp_proc_release() and l2tp_dfs_seq_release() paths free seq_file state without dropping retained tunnel or session references when the procfs or debugfs file closes before EOF. Repeated local opens and early closes can retain kernel objects until resource exhaustion interrupts service.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reference-count leakage in Linux L2TP 4.17 and affected backports allows local users to exhaust resources through partial reads. The pppol2tp_proc_release() and l2tp_dfs_seq_release() paths free seq_file state without dropping retained tunnel or session references when the procfs or debugfs file closes before EOF. Repeated local opens and early closes can retain kernel objects until resource exhaustion interrupts service.

The record

CVE
CVE-2026-74735
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-911, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 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=0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443 <9006c116dd111d457bf5d074990210f70a4ad2c8
  2. Affected versionversion=0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443 <ebe2774e956482dd3c70b8991f6f7654356339e6
  3. Affected versionversion=3.16.60 <3.17
  4. Affected versionversion=4.16.6 <4.17
  5. Affected versionversion=4.17
  6. Affected versionversion=7f8e401f9e612df2a95c1ef76217c00181389bb5
  7. Affected versionversion=9a8863e8a8def9d88583cd9c60db38a008e6b8cf
  8. Affected versionversion=c712ed63e9b33d9a282fbd92ce25c64918c3129f
  9. Affected versionversion=f6104e9ae04462523c372928b1173766a771ef95

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443 <9006c116dd111d457bf5d074990210f70a4ad2c8; version=0e0c3fee3a59a387aeecc4fca6f3a2e9615a5443 <ebe2774e956482dd3c70b8991f6f7654356339e6; version=3.16.60 <3.17; version=4.16.6 <4.17; version=4.17; version=7f8e401f9e612df2a95c1ef76217c00181389bb5; version=9a8863e8a8def9d88583cd9c60db38a008e6b8cf; version=c712ed63e9b33d9a282fbd92ce25c64918c3129f; version=f6104e9ae04462523c372928b1173766a771ef95

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-911Improper Update of Reference Count
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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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