CVE-2026-64091
Linux batman-adv TOCTOU race may cause kernel memory corruption
Is CVE-2026-64091 being exploited?
Not confirmed. CVE-2026-64091 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 0.43% probability of exploitation in the next 30 days.
How severe is CVE-2026-64091?
CVE-2026-64091 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-2026-64091?
Yes. A fix has been recorded for CVE-2026-64091. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-64091 affect?
CVE-2026-64091 affects Linux kernel (batman-adv module), Systems using batman-adv mesh interfaces. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-64091?
Apply vendor kernel/batman-adv updates and reboot affected hosts immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
TOCTOU can cause heap buffer overflow and kernel memory corruption, enabling kernel crashes or local privilege escalation via batman-adv mesh interfaces.
Immediate action required
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666b
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < 724a8eb4155669797c96b70d70e354284ae3b5a8
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < 211ea59988e1cba43cb0367ad65d379b56f9c3bd
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < 65a1e67339aa8c95ac544b796946af388930ee23
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < b4d4efd4e351593c81e9293d4b4408d244fa5ee7
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < 4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227f
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < 9a9c859457bc440a55773e01ff18b1bb5bab6836
- affected>= 16116dac23396e73c01eeee97b102e4833a4b205 and < 94d27005016be15ffc638b2ecbc4d58805ad7b48
- affected3134c5a32810c510f1f447c135cec346acbb71c3
- affectede861e03a1b5b615ad1b57b1802b17e260eedccfe
- affected0b81edc8818903c64c4d121bc51cd5825be8cc67
- affected90ae6475b1753f0c1a4c66034b5666de3189fac8
- affected>= 3.16.60 and < 3.17
- affected>= 4.4.217 and < 4.5
- affected>= 4.9.217 and < 4.10
- affected>= 4.14.174 and < 4.15
- affected4.17
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.