CVE-2026-98099: Linux kernel · ipv6: mcast: use rcu_assign_pointer() for __rcu list updates
Source GCVE Database
Not known to be exploited · CVSS 4.7 Medium · fixed in afca229b39acc2590976b3e4f6e0fe76cededc60 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 22:27 UTC
- Patch
- Available – fixed in afca229b39acc2590976b3e4f6e0fe76cededc60, 49d7e1b456ba2f3ee08b3e264d999c09992cde8e, 2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6 +2
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix has been implemented in the Linux kernel source code to address this issue by using rcu_assign_pointer() consistently for RCU list updates along with appropriate dereference helpers. Users should apply the official kernel updates or patches that include this fix. Since this is a kernel-level issue, upgrading to a fixed kernel version is the recommended remediation. No other mitigations are indicated.
Description
CVE-2026-98099 is a medium severity vulnerability in the Linux kernel's IPv6 multicast implementation. It involves improper updates to RCU-protected lists using direct pointer assignments instead of the required rcu_assign_pointer() function. This can cause race conditions with concurrent lockless readers, potentially leading to denial of service due to kernel instability or crashes. The issue affects multiple functions in net/ipv6/mcast.c related to multicast group list management. The vulnerability has been fixed by consistently applying rcu_assign_pointer() and appropriate dereference helpers.
References
- nvd.nist.gov/vuln/detail/CVE-2026-98099 (opens in a new tab)
- git.kernel.org/stable/c/0c8f56c583c3250408367880c98e4d6fbc929315 (opens in a new tab)
- git.kernel.org/stable/c/0e3e3cec28c4d1bf29948da40b4e9e5d44f7852b (opens in a new tab)
- git.kernel.org/stable/c/2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6 (opens in a new tab)
- git.kernel.org/stable/c/49d7e1b456ba2f3ee08b3e264d999c09992cde8e (opens in a new tab)
- git.kernel.org/stable/c/afca229b39acc2590976b3e4f6e0fe76cededc60 (opens in a new tab)