VulnerabilityPublished 18 Oct 2026

CVE-2026-98596: Linux kernel · ipv6: Fix dst leak for uncached routes.

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in f9722746df13a8a29103c847ef56b02c11ce0963 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in f9722746df13a8a29103c847ef56b02c11ce0963, ed902d5546fb9c142b3216d8eec914fa1bc0aa80, be31fe6333f534155e6b408f1ef6d77974bb41aa +1

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to f9722746df13a8a29103c847ef56b02c11ce0963, ed902d5546fb9c142b3216d8eec914fa1bc0aa80, be31fe6333f534155e6b408f1ef6d77974bb41aa or 5045aa25f3790dcdb158a58ac60ccf8da42959aa.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 98aa546af5e4f180439c82da403cc77926d3953b, < f9722746df13a8a29103c847ef56b02c11ce0963	Fixed in f9722746df13a8a29103c847ef56b02c11ce0963
LinuxLinux	Affected ≥ 98aa546af5e4f180439c82da403cc77926d3953b, < ed902d5546fb9c142b3216d8eec914fa1bc0aa80	Fixed in ed902d5546fb9c142b3216d8eec914fa1bc0aa80
LinuxLinux	Affected ≥ 98aa546af5e4f180439c82da403cc77926d3953b, < be31fe6333f534155e6b408f1ef6d77974bb41aa	Fixed in be31fe6333f534155e6b408f1ef6d77974bb41aa
LinuxLinux	Affected ≥ 98aa546af5e4f180439c82da403cc77926d3953b, < 5045aa25f3790dcdb158a58ac60ccf8da42959aa	Fixed in 5045aa25f3790dcdb158a58ac60ccf8da42959aa
LinuxLinux	Affected =6.11	Fixed in–

AI-suggested

A fix is available and has been applied in Linux kernel versions after 6.11, as identified by the specified commit hashes. Users should update to a fixed kernel version containing these commits to remediate the issue. No additional mitigation is required beyond applying the official patch.

Description

A vulnerability in the Linux kernel IPv6 implementation caused a memory leak of destination cache (dst) structures for uncached routes when devices are unregistered. This was due to a race condition in handling the uncached route list, leading to improper reference counting and resource leaks. The issue affects Linux kernel version 6.11 and has been fixed in subsequent commits.

Impact

The vulnerability causes a memory leak of destination cache structures and associated device references in the Linux kernel IPv6 stack when devices are unregistered. This can lead to resource exhaustion over time, potentially degrading system performance or stability. There is no indication of direct code execution or privilege escalation from this flaw.

Summary

The Linux kernel IPv6 subsystem had a flaw in managing uncached routes when a network device is unregistered. The functions ip6_route_output_flags(), ip6_rt_put_flags(), and ip6_dst_check() detect uncached routes using list_empty(&rt->dst.rt_uncached), but concurrent execution of list_del_init() could cause list_empty() to return true incorrectly. This led to ip6_route_output_flags() calling dst_hold_safe() improperly and ip6_rt_put_flags() skipping ip6_rt_put(), resulting in a leak of the dst structure and the associated device reference. The vulnerability does not affect IPv4. The issue was partially addressed by a previous commit fixing races in rt6_uncached_list_del(), but this fix fully resolves the race by checking rt6->dst.rt_uncached_list instead. The vulnerability is fixed in Linux kernel versions identified by commits f9722746df13a8a29103c847ef56b02c11ce0963, ed902d5546fb9c142b3216d8eec914fa1bc0aa80, be31fe6333f534155e6b408f1ef6d77974bb41aa, and 5045aa25f3790dcdb158a58ac60ccf8da42959aa.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:10 UTC

Technical details

References

Community reviews

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