Linux Kernel up to 6.12.111/6.18.54/7.2.8/7.3-rc4 ipv6 memory leak

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.7$0-$5k0.00

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel up to 6.12.111/6.18.54/7.2.8/7.3-rc4. This affects the function ip6_route_output_flags/ip6_rt_put_flags/ip6_dst_check of the component ipv6. The manipulation results in memory leak. This vulnerability is cataloged as CVE-2026-98596. The attack may be launched remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.111/6.18.54/7.2.8/7.3-rc4. Affected is the function ip6_route_output_flags/ip6_rt_put_flags/ip6_dst_check of the component ipv6. 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. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ipv6: Fix dst leak for uncached routes. ip6_route_output_flags(), ip6_rt_put_flags(), and ip6_dst_check() detect an uncached route by list_empty(&rt->dst.rt_uncached), which replaced the static DST_NOCACHE flag check in commit a4c2fd7f7891 ("net: remove DST_NOCACHE flag"). When a device is unregistered, rt6_uncached_list_flush_dev() unlinks uncached routes tied to the device from rt6_uncached_list. Previously, they were moved to another list with list_move() (__list_del_entry() + list_add()), and since commit 98aa546af5e4 ("inet: remove (struct uncached_list)->quarantine"), the routes are just unlinked with list_del_init(). If list_del_init() runs concurrently, list_empty() evaluates to true; ip6_route_output_flags() calls dst_hold_safe() incorrectly and ip6_rt_put_flags() skips ip6_rt_put(), leaking dst, and thus dev tied via rt->from as well. The same race is partially fixed by commit 9a6f0c4d5796 ("dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()"). Let's check rt6->dst.rt_uncached_list instead. Note that IPv4 does not have the same issue.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-98596 since 09/25/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Additional levels of successful authentication are needed for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/18/2026). This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 6.12.112, 6.18.55, 7.2.9 or 7.3-rc5 eliminates this vulnerability. Applying the patch 5045aa25f3790dcdb158a58ac60ccf8da42959aa/ed902d5546fb9c142b3216d8eec914fa1bc0aa80/f9722746df13a8a29103c847ef56b02c11ce0963/be31fe6333f534155e6b408f1ef6d77974bb41aa 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

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
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 6.12.112/6.18.55/7.2.9/7.3-rc5
Patch: 5045aa25f3790dcdb158a58ac60ccf8da42959aa/ed902d5546fb9c142b3216d8eec914fa1bc0aa80/f9722746df13a8a29103c847ef56b02c11ce0963/be31fe6333f534155e6b408f1ef6d77974bb41aa

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-2026-98596 (🔒)
GCVE (CVE): GCVE-0-2026-98596
GCVE (VulDB): GCVE-100-422094

Entryinfo

Created: 10/18/2026 20:18
Changes: 10/18/2026 20:18 (59)
Complete: 🔍
Cache ID: 216::103

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