CVE-2026-5067
Remote attacker can corrupt memory in Zephyr's WebSocket upgrade path.
Is CVE-2026-5067 being exploited?
Not confirmed. CVE-2026-5067 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 0.64% probability of exploitation in the next 30 days.
How severe is CVE-2026-5067?
CVE-2026-5067 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-2026-5067?
Yes. A fix has been recorded for CVE-2026-5067. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-5067 affect?
CVE-2026-5067 affects Zephyr HTTP server (WebSocket upgrade path). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-5067?
Patch when available; disable WebSocket upgrade if not required.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Out-of-bounds read/write on stack via crafted Sec-WebSocket-Key; DoS and potential code execution.
Patch when possible
- affected>= 3.7.0 and <= 4.3.0
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.