Kernel-level bug in the Linux xfrm/IPsec path affecting widely deployed Linux systems; can enable kernel memory corruption leading to crashes or RCE across servers and appliances.
CVE-2026-72451
Linux kernel xfrm race causes kernel memory corruption and possible RCE.
Is CVE-2026-72451 being exploited?
Not confirmed. CVE-2026-72451 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 0.66% probability of exploitation in the next 30 days.
How severe is CVE-2026-72451?
CVE-2026-72451 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-2026-72451?
Yes. A fix has been recorded for CVE-2026-72451. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72451 affect?
CVE-2026-72451 affects Linux kernel (xfrm/IPsec), Linux distributions with vulnerable kernels, Servers, routers, network appliances using affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72451?
Apply vendor kernel updates and reboot; block/untrust IPsec traffic until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted IPsec/xfrm packets can trigger a use-after-free, causing kernel crash, privilege escalation to root, or remote code execution.
Immediate action required
- affected>= 5e4334dc39443645415450163ff5ff1ee7e79784 and < 6dab4dec9a49121d079981ac913569f232c06b06
- affected>= 81a331a0e72ddc2f75092603d9577bd1a0ca23ad and < a1a3360a0c44b8b5c134db2a9d0667b61c9cf523
- affected>= 81a331a0e72ddc2f75092603d9577bd1a0ca23ad and < 041859fd55c81ea55e76d051e39b7b79975b8c7d
- affected>= 81a331a0e72ddc2f75092603d9577bd1a0ca23ad and < ddd3d0132920319ac426e12456013eadbae67e15
- affected>= 6.12.13 and < 6.12.97
- affected6.13
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.