Linux kernel eBPF bug affects core OS across distributions; can lead to host compromise and impacts broad enterprise infrastructure.
CVE-2026-72423
Linux kernel eBPF conntrack write bug can corrupt kernel memory.
Is CVE-2026-72423 being exploited?
Not confirmed. CVE-2026-72423 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 0.15% probability of exploitation in the next 30 days.
How severe is CVE-2026-72423?
CVE-2026-72423 is rated High with a CVSS score of 8.8. 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-2026-72423?
Yes. A fix has been recorded for CVE-2026-72423. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72423 affect?
CVE-2026-72423 affects Linux kernel (BPF conntrack kfuncs), eBPF-enabled systems, Linux distributions with affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72423?
Apply vendor/kernel patches or backported fixes; restrict unprivileged BPF until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Out-of-bounds write via eBPF conntrack opts leads to kernel memory corruption, enabling local privilege escalation or host compromise.
Immediate action required
- affected>= b4c2b9593a1c4c3a718370e34af28e817fd5e5c6 and < dd74c80203842a21b2ebb9f70d1260d9aa20fa05
- affected>= b4c2b9593a1c4c3a718370e34af28e817fd5e5c6 and < 6f6183a39533d727deaa5061cadae6dd9e6744d0
- affected5.18
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.