Linux Kernel up to 6.12.112/6.18.55/7.2.9/7.3-rc5 Netfilter Flow Offload nft_flow_offload_init release of resource

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6.2	$0-$5k	1.37-

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.12.112/6.18.55/7.2.9/7.3-rc5. Affected is the function nft_flow_offload_init of the component Netfilter Flow Offload. The manipulation leads to release of resource. This vulnerability is documented as CVE-2026-98851. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.112/6.18.55/7.2.9/7.3-rc5 and classified as critical. This issue affects the function nft_flow_offload_init of the component Netfilter Flow Offload. The manipulation with an unknown input leads to a release of resource vulnerability. Using CWE to declare the problem leads to CWE-772. The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_flow_offload: drop flowtable reference on init error path nft_flow_offload_init() bumps the flowtable use count with nft_use_inc() before calling nf_ct_netns_get(). When the latter fails, the error is returned as-is and the reference is leaked. The upper layers do not balance it either: nf_tables_newexpr() clears expr->ops when the expression init callback fails, so the nft_expr_more() iteration in nft_rule_expr_deactivate() and nf_tables_rule_destroy() stops right before the failed expression and its ->destroy callback, which would drop the reference, never runs. Each failed rule addition therefore leaks one flowtable reference and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE keeps reporting -EBUSY even though no rule references it. Save the nf_ct_netns_get() return value and undo the nft_use_inc() when it fails, restoring the inc/dec pairing within nft_flow_offload_init() itself.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-98851 since 09/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. 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 10/18/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 6.12.113, 6.18.56, 7.2.10 or 7.3-rc6 eliminates this vulnerability. Applying the patch 64ac0cb574c740bf723affb79b646eeba920db6b/c5f91098edee98c015f78488460a0609e62582a5/4cd378423a33194a773c267fc58606d28fce95cf/747928b5d4ff8c8de55138a54c13980e4bb88578 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.112
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 6.18.51
• 6.18.52
• 6.18.53
• 6.18.54
• 6.18.55
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.3-rc1
• 7.3-rc2
• 7.3-rc3
• 7.3-rc4
• 7.3-rc5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Release of resource
CWE: CWE-772 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

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Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.113/6.18.56/7.2.10/7.3-rc6
Patch: 64ac0cb574c740bf723affb79b646eeba920db6b/c5f91098edee98c015f78488460a0609e62582a5/4cd378423a33194a773c267fc58606d28fce95cf/747928b5d4ff8c8de55138a54c13980e4bb88578

Timelineinfo

09/25/2026 CVE reserved
10/18/2026 +23 days Advisory disclosed
10/18/2026 +0 days VulDB entry created
10/18/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98851 (🔒)
GCVE (CVE): GCVE-0-2026-98851
GCVE (VulDB): GCVE-100-421871

Entryinfo

Created: 10/18/2026 18:40
Changes: 10/18/2026 18:40 (59)
Complete: 🔍
Cache ID: 216::103

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