Linux kernel vulnerability in SCTP affects widely deployed OSes and network stacks; high-severity kernel exploit would be widely newsworthy and disruptive.
CVE-2026-89478
Linux kernel SCTP use-after-free allowing kernel memory corruption (high severity).
Is CVE-2026-89478 being exploited?
Not confirmed. CVE-2026-89478 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-89478?
CVE-2026-89478 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-89478?
Yes. A fix has been recorded for CVE-2026-89478. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89478 affect?
CVE-2026-89478 affects Linux kernel (SCTP subsystem), Linux servers, Network appliances using Linux, Cloud VM instances running Linux. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89478?
Apply vendor/kernel security updates; disable or block SCTP if not needed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Use-after-free in SCTP can cause kernel memory corruption; attacker with an SCTP association can crash the kernel (DoS) or potentially achieve kernel RCE.
Immediate action required
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < c6c86a5e62a4fec36692ddd64b9144b660f71f96
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 1035bdef1efb9b1076d1a57b81e08c637ff08ecc
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 3537961df2163258bddc230db0e18dc14e925ea6
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 03a9d10ecf71f54b2af8020935f2033d4a132be5
- affected2.6.12
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.