Linux TCP flaw prompts patching and kernel-status checks
Technology · First reported 30 Oct, 02:33 · Updated 03:33
CVE-2026-98432 is a use-after-free in Linux’s IPv4 TCP handshake path. The supplied accounts describe an upstream fix, distribution-specific patch status, and a reported remote-root exploit in a specific Multipath TCP configuration; administrators are advised to verify their vendor’s kernel status and reboot after installing a fix.
- The flaw affects Linux’s IPv4 TCP handshake path, where saved IP options can be freed while another processor is still using them.
- The upstream correction delays freeing the affected memory until RCU readers have finished; whether a distribution has shipped that fix depends on its kernel package and release.
- Anthropic reported a lab exploit that achieved remote root command execution on a server with an MPTCP listener; the report does not establish that the same exploit works on every Linux configuration.
Summary written by Lux AI from 2 articlesUnverified
Key facts
- CVE
- CVE-2026-98432.
- Upstream severity
- The Linux kernel CNA assigns CVSS 3.1 score 9.8, Critical.
- Upstream fix
- The fix uses RCU-aware freeing to defer reclamation until readers finish.
- Reported exploit
- Anthropic said its Claude model produced a remote-root proof of concept for a server with an MPTCP listener; the exploit was not published in the account.
- Status snapshot
- Atlas reports that, as of October 29, 2026, Ubuntu still listed its kernels as vulnerable and RHEL 8, 9, and 10 as affected without a fix.
Source spectrum
Left 0 · Centre 0 · Right 0 of 0 rated sources · +2 unrated
All coverage
Coverage over time
LeftCentreRight
Articles per hour since first reported, by side.
Ownership
- Unknown 100% (2)
Share of the 2 sources by owner type.