CVE-2026-8836
Remote stack-based overflow in lwIP SNMP USM handler.
Is CVE-2026-8836 being exploited?
Not confirmed. CVE-2026-8836 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 1.1% probability of exploitation in the next 30 days.
How severe is CVE-2026-8836?
CVE-2026-8836 is rated Critical with a CVSS score of 9.3. 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-2026-8836?
Yes. A fix has been recorded for CVE-2026-8836. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What should I do about CVE-2026-8836?
Apply official patch to fix lwIP SNMP USM overflow.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote overflow via crafted SNMP inbound frame; potential remote code execution or device crash.
Immediate action required
- affected2.1.0
- affected2.1.1
- affected2.1.2
- affected2.1.3
- affected2.2.0
- affected2.2.1
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.