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major vulnerability· requires attention

U-Boot is a widely used bootloader across embedded, network and industrial devices; bootloader RCE can compromise fleets and persist across reboots.

Systems

CVE-2026-15390

9.0
Critical
EPSS n/aPatch availableSep 29, 2026

U-Boot IP defragmentation flaw permits remote RCE via crafted fragmented IP packets.

common questions

Is CVE-2026-15390 being exploited?

Not confirmed. CVE-2026-15390 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.

How severe is CVE-2026-15390?

CVE-2026-15390 is rated Critical with a CVSS score of 9.0. 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-2026-15390?

Yes. A fix has been recorded for CVE-2026-15390. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-15390 affect?

CVE-2026-15390 affects Das U-Boot bootloader (embedded devices), Routers, IoT devices, Industrial/OT devices using U-Boot. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-15390?

Upgrade U-Boot to 2026.07 or apply vendor patch; block/inspect fragmented IP traffic.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
Das U-Boot bootloader (embedded devices)RoutersIoT devicesIndustrial/OT devices using U-Boot
impact

Remote arbitrary code execution by sending duplicated last-fragment IP packets during IP reassembly, enabling persistent device compromise.

action required

Immediate action required

affected versions
DENX Software Engineering Das U-Boot
  • affected>= 2009.08 and <= 2026.07

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.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
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