Linux Kernel up to 7.0-rc2 recv_vcc lec_arp_clear_vccs memory leak

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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.0-rc2. The impacted element is the function lec_arp_clear_vccs of the component recv_vcc. The manipulation leads to memory leak. This vulnerability is uniquely identified as CVE-2026-23286. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.0-rc2. It has been rated as critical. This issue affects the function lec_arp_clear_vccs of the component recv_vcc. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: atm: lec: fix null-ptr-deref in lec_arp_clear_vccs syzkaller reported a null-ptr-deref in lec_arp_clear_vccs(). This issue can be easily reproduced using the syzkaller reproducer. In the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by multiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc). When the underlying VCC is closed, lec_vcc_close() iterates over all ARP entries and calls lec_arp_clear_vccs() for each matched entry. For example, when lec_vcc_close() iterates through the hlists in priv->lec_arp_empty_ones or other ARP tables: 1. In the first iteration, for the first matched ARP entry sharing the VCC, lec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back) and sets vcc->user_back to NULL. 2. In the second iteration, for the next matched ARP entry sharing the same VCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from vcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it via `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash. Fix this by adding a null check for vpriv before dereferencing it. If vpriv is already NULL, it means the VCC has been cleared by a previous call, so we can safely skip the cleanup and just clear the entry's vcc/recv_vcc pointers. The entire cleanup block (including vcc_release_async()) is placed inside the vpriv guard because a NULL vpriv indicates the VCC has already been fully released by a prior iteration — repeating the teardown would redundantly set flags and trigger callbacks on an already-closing socket. The Fixes tag points to the initial commit because the entry->vcc path has been vulnerable since the original code. The entry->recv_vcc path was later added by commit 8d9f73c0ad2f ("atm: fix a memory leak of vcc->user_back") with the same pattern, and both paths are fixed here.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-23286 since 01/13/2026. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 311783 (Debian dla-4561 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7 or 7.0-rc3 eliminates this vulnerability. Applying the patch e9665986eb127290ceb535bd5d04d7a84265d94f/622062f24644b4536d3f437e0cf7a8c4bb421665/2d9f57ea29a1f1772373b98a509b44d49fda609e/7ea92ab075d809ec8a96669a5ecf00f752057875/5f1cfea7921f5c126a441d973690eeba52677b64/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (311783) and CERT Bund (WID-SEC-2026-0861). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • F5 BIG-IP

Productinfo

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 311783
Nessus Name: Debian dla-4561 : linux-config-6.1 - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.167/6.6.130/6.12.77/6.18.17/6.19.7/7.0-rc3
Patch: e9665986eb127290ceb535bd5d04d7a84265d94f/622062f24644b4536d3f437e0cf7a8c4bb421665/2d9f57ea29a1f1772373b98a509b44d49fda609e/7ea92ab075d809ec8a96669a5ecf00f752057875/5f1cfea7921f5c126a441d973690eeba52677b64/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb

Timelineinfo

01/13/2026 CVE reserved
03/25/2026 +71 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
07/01/2026 +98 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23286 (🔒)
GCVE (CVE): GCVE-0-2026-23286
GCVE (VulDB): GCVE-100-352997
CERT Bund: WID-SEC-2026-0861 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 03/25/2026 12:05
Updated: 07/01/2026 17:48
Changes: 03/25/2026 12:05 (59), 03/26/2026 02:18 (7), 03/29/2026 23:37 (1), 05/03/2026 18:48 (2), 06/01/2026 00:36 (10), 06/16/2026 14:09 (1), 07/01/2026 17:48 (1)
Complete: 🔍
Cache ID: 216::103

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