Cisco
US networking and cybersecurity giant; manufacturer of ASA and Firepower firewall appliances exploited by UAT-4356.
Cisco's firewall and network-management products faced repeated confirmed exploitation in 2026, with CISA listing a hard-coded-password flaw on 29 July after an 18-year-old router flaw reappeared on 14 July.
Last refreshed: 22 September 2026 · Appears in 2 active topics
Seven SD-WAN CVEs in one calendar year: is Cisco's edge portfolio structurally compromised?
Timeline for Cisco
Took four three-day KEV entries in three weeks
Cybersecurity: Threats and Defences: Cisco reaches 100 entries on CISA's listMentioned in: NVIDIA lines up $500bn for buyers
Data Centres: Boom and BacklashMentioned in: Samsung and SoftBank bank the demand
AI: Jobs, Power & MoneyMentioned in: KEV patch clocks fell to three days
Cybersecurity: Threats and DefencesMentioned in: Arista, Fortinet and Cisco flaws listed
Cybersecurity: Threats and DefencesBackground
Cisco is a US networking and cybersecurity company that makes enterprise network equipment and security products, including ASA and Firepower firewall appliances. Its products connect sites, manage network traffic and protect organisational network boundaries.
That installed role makes Cisco's security engineering and recovery process part of customers' operational risk. On 24 April, CISA and the UK's National Cyber Security Centre disclosed FIRESTARTER, a back door in Cisco firewall startup code that could survive routine patching and required a full power-down and cold restart for removal.
Cisco matters because its equipment often sits at network edges and in central management roles. On 20 April, CISA gave federal agencies three days to remediate three actively exploited flaws in Cisco SD-WAN Manager, illustrating how a software weakness can quickly become an estate-wide response task.
Cisco faces recurring exploited flaws
On 14 July, CISA added an 18-year-old Cisco router flaw to its Known Exploited Vulnerabilities catalogue, indicating current exploitation despite a fix having existed since 2008. The entry returned legacy Cisco deployments to the urgent remediation cycle.
On 29 July, CISA listed CVE-2026-20316, a hard-coded password flaw in Cisco Secure Firewall Management Center, with a three-day Deadline. For Cisco, the two entries show exposure across both long-lived network software and firewall-management tooling, increasing the operational burden on customers running mixed estates.
Cisco shifts spending towards AI
On 14 May, Cisco cut roughly 4,000 staff while reporting a record $15.8bn quarterly revenue. Chief executive Chuck Robbins raised the company's target for AI-hardware orders to about $9bn, tying the workforce reduction to investment priorities rather than weaker demand.
For Cisco, the decision placed AI infrastructure at the centre of capital allocation during a strong results period. The cut became a concrete signal that growth in networking demand did not protect every part of the organisation from a shift towards hardware orders and related investment.