CVE-2026-98432: Linux kernel · ipv4: free inet_opt and ireq_opt after an RCU grace period
Source GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in e3f33b0a1d89d738e2b913dab519226eaf76e15b : patch Linux kernel as a priority.
Data as of 30 Oct 2026, 06:59 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 9.8 |
|---|
- 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
Weaponized: 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 29 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 that changes the freeing of inet_opt and ireq_opt to use kfree_rcu(), ensuring memory is freed only after an RCU grace period. Users should apply the official Linux kernel patches addressing this issue. Since this is a kernel vulnerability, upgrading to a patched kernel version is the recommended mitigation. No other specific mitigations are indicated.
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 inet_opt and ireq_opt options are freed improperly without waiting for an RCU grace period, leading to potential memory corruption during SYNACK packet construction. IPv6 is not affected by the main issue but has a related migration issue to be patched separately.
References
- nvd.nist.gov/vuln/detail/CVE-2026-98432 (opens in a new tab)
- git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568 (opens in a new tab)
- git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936 (opens in a new tab)
- git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a (opens in a new tab)
- git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036 (opens in a new tab)
- git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5 (opens in a new tab)
- git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2 (opens in a new tab)
- git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6 (opens in a new tab)
- git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b (opens in a new tab)
- openwall.com/lists/oss-security/2026/10/30/1 (opens in a new tab)