CVE-2026-72398
Linux kernel SCTP cookie unpacking allows authentication bypass in handshake
Is CVE-2026-72398 being exploited?
Not confirmed. CVE-2026-72398 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 0.70% probability of exploitation in the next 30 days.
How severe is CVE-2026-72398?
CVE-2026-72398 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-2026-72398?
Yes. A fix has been recorded for CVE-2026-72398. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72398 affect?
CVE-2026-72398 affects Linux kernel (SCTP subsystem). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72398?
Apply vendor kernel patch immediately; enable SCTP cookie_auth or block SCTP (IP proto 132) if unused
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Auth bypass in SCTP handshake via crafted COOKIE-ECHO; attacker can forge associations to establish unauthorized connections, inject traffic, or cause DoS.
Immediate action required
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < bca3100f550281c2f2418652338bced3b35af0e6
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 062bcbf8d1f1051fdeb20b94920031b0e2cb95a2
- affected>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 414c5447fe6a200613dd46d7fdc8454622076cb1
- 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.