Cisco network/security products are widely deployed; CVSS 9.9 improper-access flaws could enable administrative takeover and disrupt infrastructure, warranting broad IT attention.
CVE-2026-76299
Critical Cisco access-control flaws enabling high-impact unauthorized access.
Is CVE-2026-76299 being exploited?
Not confirmed. CVE-2026-76299 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 0.33% probability of exploitation in the next 30 days.
How severe is CVE-2026-76299?
CVE-2026-76299 is rated Critical with a CVSS score of 9.9. 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-2026-76299?
Yes. A fix has been recorded for CVE-2026-76299. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-76299 affect?
CVE-2026-76299 affects Cisco networking and security software (unspecified), Enterprise routers, switches, firewalls. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-76299?
Apply vendor hardening updates immediately and review access controls.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Improper access control may allow remote unauthorized access, privilege escalation, or administrative takeover of network/security devices.
Immediate action required
- affected>= 10.4 and < 10.4.4
- affected>= 10.2 and < 10.2.8
- affected>= 10.0 and < 10.0.11
- affected>= 9.4 and < 9.4.16
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.