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VulnerabilityPublished Updated

CVE-2026-98432: Linux kernel · ipv4: free inet_opt and ireq_opt after an RCU grace period

Affects Linux kernelSource CVE Database V5

0

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

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
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:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 079096f103faca2dd87342cca6f23d4b34da8871, < e3f33b0a1d89d738e2b913dab519226eaf76e15b
Fixed in
  • e3f33b0a1d89d738e2b913dab519226eaf76e15b
LinuxLinuxAffected
  • ≥ 079096f103faca2dd87342cca6f23d4b34da8871, < b3b027ef0cd322bfa839b9aaf5b27551eea54cf6
Fixed in
  • b3b027ef0cd322bfa839b9aaf5b27551eea54cf6
LinuxLinuxAffected
  • ≥ 079096f103faca2dd87342cca6f23d4b34da8871, < a47406c769f72c070386985488f1c4d057df86b2
Fixed in
  • a47406c769f72c070386985488f1c4d057df86b2
LinuxLinuxAffected
  • ≥ 079096f103faca2dd87342cca6f23d4b34da8871, < 742f73df544e03744f2981c467d6542fe8172a2a
Fixed in
  • 742f73df544e03744f2981c467d6542fe8172a2a
LinuxLinuxAffected
  • ≥ 079096f103faca2dd87342cca6f23d4b34da8871, < 95a8c8fa9f27dce64c40c41c062de7728bf34ab5
Fixed in
  • 95a8c8fa9f27dce64c40c41c062de7728bf34ab5
LinuxLinuxAffected
  • ≥ 079096f103faca2dd87342cca6f23d4b34da8871, < 89b5b1eb7d633c33832b7ff2c02e19a144705036
Fixed in
  • 89b5b1eb7d633c33832b7ff2c02e19a144705036

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

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