Cisco Discovers 5 Critical Security Vulnerabilities in Its Software
Four critical and one high-severity flaws pose significant threats to users.
1Cisco's Security Vulnerabilities
Cisco has identified five security vulnerabilities in its Secure Workload Software micro-segmentation tool, including four critical and one high-severity flaw. These vulnerabilities could allow attackers to move laterally within networks. The two most critical flaws, CVE-2026-20315 and CVE-2026-20317, both involve access control issues and were given the maximum CVSS score of 10.
2Perfect 10 Vulnerabilities
CVE-2026-20315 covers authorization, authentication, privileges, and bypass issues. CVE-2026-20317 relates to missing authentication, authentication bypass, and reliance on untrusted inputs. Both vulnerabilities received a perfect 10/10 CVSS score, indicating the highest risk level. Cisco has not shared detailed technical information about these flaws.
3Other Significant Flaws
CVE-2026-20231 scored 9.9 and involves improper neutralization of special elements. CVE-2026-20318 received a 9.6 score for improper input validation. The least severe of the group, CVE-2026-20319, scored 7.5 and relates to improper restriction of operations within memory buffers, including overflows and out-of-bounds writes.
4Patches and Updates
Cisco has fixed these vulnerabilities in its SaaS version, but users need to update their Agent and Connector tools. On-premises users running version 3.10 or earlier must upgrade to 3.10.9.1, while those using version 4.0 or later need to move to 4.0.4.16. The company stated there's no evidence of malicious exploitation so far.
5Discovery Process
Cisco announced these vulnerabilities on Thursday, discovered through a 'comprehensive internal security review' that included existing testing processes and frontier AI models. Cisco is known to participate in Project Glasswing, which provides access to Anthropic's Mythos bug-finding model that isn't publicly available, possibly used in this research.
6Micro-Segmentation Technology
Secure Workload Software (formerly Tetration) aims to prevent lateral movement by attackers through micro-segmentation of network workloads. Offered as both SaaS and on-premises solutions, this product plays a critical role in enterprise network security and is widely used by large organizations.
7CVSS Scoring System
The Common Vulnerability Scoring System (CVSS) evaluates vulnerability severity on a 0-10 scale: 9.0-10.0 is critical, 7.0-8.9 is high, 4.0-6.9 is medium, and 0.1-3.9 is low. Cisco's vulnerabilities include two perfect 10s, one 9.9, one 9.6, and one 7.5, representing extremely serious risk levels that demand immediate attention.
8Enterprise Impact
These vulnerabilities pose significant risks for large organizations using Cisco's network security solutions. Successful exploitation could allow attackers widespread movement within corporate networks and access to sensitive data. Cisco's rapid patch release and users' immediate application of these updates are critically important for security.