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- Zero-days, Malware & exploits
- Vulnerabilities
- 1 CVE Exploited
For the fifth time this year, Cisco revealed attackers have exploited a vulnerability (CVE-2026-76504) in its SD-WAN solution in zero-day attacks. The vendor’s incident responders became aware of active exploitation of this vulnerability in September 2026, after getting pinged and resolving a Cisco Technical Assistance Center (TAC) support case. Cisco has yet to share any…
If you run the affected product
- Find every instance – especially the ones reachable from the internet.
- Apply the vendor's patch or mitigation now: exploited flaws are fixed in days, not at the next patch cycle.
- Then check for signs it was used before you patched: web shells, new accounts, unusual outbound traffic.
More helpCISA's Known Exploited Vulnerabilities catalogue (opens in a new tab)
The vulnerabilities in this story
CVE-2026-76504 in the NVD (opens in a new tab)
- CVSS9.8Critical
- EPSS1.8%chance of exploitation in 30 days
- CISA KEVExploitedon the list since 30 Sep
Exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog (CC0). Exploit prediction: EPSS by FIRST. This product uses the NVD API but is not endorsed or certified by the NVD.
Defender’s notebook
The attacker technique behind this story, in MITRE’s terms – and what to check in your own estate.
Exploit Public-Facing Application
Initial AccessWhat a defender checks
- Find every internet-facing instance of the affected product.
- Patch, or apply the vendor's mitigation now – CISA's KEV list gives a deadline.
- Look for signs it was exploited before you patched: web shells, new accounts, odd outbound traffic.
Build the skillBlue Team Analyst · Vulnerability Management
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Blue Team Analyst · Vulnerability Management
You can't patch everything at once. Learn what to fix first.
In our Blue Team Analyst programme you run a vulnerability scan, prioritise the output with CVSS, EPSS and asset criticality, and track remediation to closure with the teams who own the fix.
- Read scanner output properly
- Prioritise with CVSS, EPSS and asset criticality
- Track remediation to closure
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