Cisco Systems, Inc. (NASDAQ:CSCO) Faces Cybersecurity Challenge Amid Stock Sale

Font: Financial Modeling Prep  • Dec 19, 2025

• Michael D. Capellas, a director at Cisco Systems, Inc. (NASDAQ:CSCO), sold 10,850 shares at $77.13 each, retaining 146,368 shares.
• Cisco disclosed a significant cybersecurity issue, CVE-2025-20393, affecting its AsyncOS software used in Secure Email Gateway and Web Manager.
• Despite the cybersecurity concerns, Cisco's stock price increased to $78.42, with a market capitalization of approximately $309.8 billion.

Cisco Systems, Inc. (NASDAQ:CSCO), a leading technology company known for its networking hardware, software, and telecommunications equipment, competes with tech giants like Juniper Networks and Huawei. On December 19, 2025, Michael D. Capellas, a director at Cisco, sold 10,850 shares of the company's common stock at $77.13 each. After this transaction, Capellas retains 146,368 shares.

The sale by Capellas comes amid a significant cybersecurity issue for Cisco. The company disclosed that hackers, allegedly backed by the Chinese government, are exploiting a vulnerability in its products. This flaw, known as CVE-2025-20393, affects the Cisco AsyncOS software, particularly impacting the Cisco Secure Email Gateway and Web Manager. The vulnerability is a zero-day flaw, meaning it was exploited before being publicly known.

Security researchers estimate that hundreds of Cisco customers could be at risk due to this vulnerability. Piotr Kijewski, CEO of the Shadowserver Foundation, noted that the exposure appears to be in the hundreds rather than thousands. The attacks are currently targeted, which may explain the limited activity observed. Despite the potential threat, the "Spam Quarantine" feature linked to the vulnerability is not enabled by default, potentially limiting the scope of the threat.

The current stock price of Cisco is $78.42, reflecting a 1.91% increase. The stock has traded between $76.79 and $79.17 today, with a market capitalization of approximately $309.8 billion. Despite the cybersecurity concerns, the stock's performance remains strong, with a trading volume of 84.39 million shares. Over the past year, Cisco's stock has reached a high of $80.82 and a low of $52.11.