Linux Kernel up to 6.18.51/7.2.5 Network Namespace copy_net_ns memory leak

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k0.41+

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.18.51/7.2.5 and classified as critical. This vulnerability affects the function copy_net_ns of the component Network Namespace. Performing a manipulation results in memory leak. This vulnerability was named CVE-2026-90077. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.51/7.2.5. It has been classified as critical. This affects the function copy_net_ns of the component Network Namespace. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: fix a resource leak in copy_net_ns() error handling path Currently, preinit_net() does two things: (1) call ns_common_init() which might fail (2) initialize resources which does not fail However, preinit_net() is returning early when (1) fails, and copy_net_ns() is jumping to the dec_ucounts: label. As a result, resources allocated by net_alloc() are leaking. We need to call key_remove_domain() and net_passive_dec() in order to release resources allocated by net_alloc(). We cannot simply jump to the put_userns: label when preinit_net() failed, for (2) is not yet done. But we can reorder (1) and (2), for there is no dependency between (1) and (2). Therefore, this patch decouples (1) from preinit_net() and changes preinit_net() back to a void function, and calls ns_common_init() after preinit_net() succeeded. Then, we can jump to immediately after ns_common_free() of the put_userns: label.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-90077 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/17/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch 76c847e80d2b6be047707d58e8e05eedbe2593ad/e69bde4eb566aea8fa97cbb93e0bab608964f1a5/3220b62fbb8a55feebd2a826d5ead0f49f09ed5a is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

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: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.52/7.2.6/7.3-rc1
Patch: 76c847e80d2b6be047707d58e8e05eedbe2593ad/e69bde4eb566aea8fa97cbb93e0bab608964f1a5/3220b62fbb8a55feebd2a826d5ead0f49f09ed5a

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90077 (🔒)
GCVE (CVE): GCVE-0-2026-90077
GCVE (VulDB): GCVE-100-406563

Entryinfo

Created: 09/17/2026 18:48
Changes: 09/17/2026 18:48 (59)
Complete: 🔍
Cache ID: 216::103

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