CVE-2026-98432: Linux kernel · ipv4: free inet_opt and ireq_opt after an RCU grace period
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in e3f33b0a1d89d738e2b913dab519226eaf76e15b : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in e3f33b0a1d89d738e2b913dab519226eaf76e15b, b3b027ef0cd322bfa839b9aaf5b27551eea54cf6, a47406c769f72c070386985488f1c4d057df86b2 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 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.
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
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AI-suggested
A fix is available and has been applied in multiple Linux kernel commits identified by the fixedVersions hashes. Users and administrators should update to a Linux kernel version that includes these fixes to mitigate this vulnerability. No additional mitigation steps are indicated beyond applying the official patches.
Description
CVE-2026-98432 is a critical use-after-free vulnerability in the Linux kernel's IPv4 TCP request socket handling. It arises because the kernel frees certain socket options (inet_opt and ireq_opt) without proper synchronization after an RCU grace period, leading to potential memory corruption when concurrent CPUs access freed memory. The flaw affects TCP child sockets and request socket migration paths, causing a use-after-free in ip_options_build(). IPv6 is not affected by the primary issue. The vulnerability has been fixed by changing the freeing mechanism to use kfree_rcu().
References
- git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6 (opens in a new tab)
- git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5 (opens in a new tab)
- git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036 (opens in a new tab)
- git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a (opens in a new tab)
- git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568 (opens in a new tab)
- git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2 (opens in a new tab)
- git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936 (opens in a new tab)
- git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b (opens in a new tab)