CVE-2026-98438: Linux kernel · mptcp: options: fix uninit-value in mptcp_write_data_fin
Affects Linux kernelSource CVE Database V5
Not known to be exploited : upgrade to b110f1dd6cb6a9930503354a01a315e0a821eaa7 or 9a682067dd7b9dce6b94a0a05661dcc921446402 when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in b110f1dd6cb6a9930503354a01a315e0a821eaa7, 9a682067dd7b9dce6b94a0a05661dcc921446402
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.
What to do
Upgrade Linux kernel to b110f1dd6cb6a9930503354a01a315e0a821eaa7 or 9a682067dd7b9dce6b94a0a05661dcc921446402.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
This vulnerability has been fixed in Linux kernel versions identified by commits b110f1dd6cb6a9930503354a01a315e0a821eaa7 and 9a682067dd7b9dce6b94a0a05661dcc921446402. Users and administrators should update to these fixed versions or later to remediate the issue.
Description
A vulnerability in the Linux kernel's Multipath TCP (MPTCP) implementation was fixed involving an uninitialized value in the mptcp_write_data_fin function. The issue occurs when sending a DATA_FIN without data, where specific DSS mapping and checksum computations are required but were not properly initialized due to changes in packet handling code. This flaw could lead to incorrect packet construction in MPTCP connections.