CVE-2026-64522
mlx5e driver underflows eswitch mode counter via IPsec acquire SA, causing kernel corruption.
Is CVE-2026-64522 being exploited?
Not confirmed. CVE-2026-64522 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 0.34% probability of exploitation in the next 30 days.
How severe is CVE-2026-64522?
CVE-2026-64522 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-2026-64522?
Yes. A fix has been recorded for CVE-2026-64522. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-64522 affect?
CVE-2026-64522 affects Linux kernel (mlx5e driver), Mellanox/NVIDIA ConnectX NICs, Servers using mlx5e offload/ESwitch. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-64522?
Update Linux kernel/mlx5e driver to patched release and reboot affected hosts.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Counter underflow can cause kernel memory corruption, potential kernel panic/DoS and may lead to privilege escalation or code execution via crafted IPsec traffic.
Patch when possible
- affected>= 22239eb258bc1e6ccdb2d3502fce1cc2b2a88386 and < b5bd4249e430f5963d559708ee96a671716d2400
- affected>= 22239eb258bc1e6ccdb2d3502fce1cc2b2a88386 and < ecafd8284e527666e83261e6e57a7c7341d591cb
- affected>= 22239eb258bc1e6ccdb2d3502fce1cc2b2a88386 and < abe003b33223ff33552f291644bf35d9c2f992fb
- affected993c4ba71596c30418ba5a0ddcf4f9c2f431466a
- affected>= 6.17.4 and < 6.18
- affected6.18
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.