CVE-2026-20188 Vulnerability Analysis & Exploit Details

CVE-2026-20188 Vulnerability Summary

CVE-2026-20188: A vulnerability in the connection-handling mechanism of Cisco Crosswork Network Controller (CNC) and Cisco Network Services Orchestrator (NSO) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected system. This vulnerability is due to an inadequate implementation of rate-limiting on incoming network connections. An attacker could exploit this vulnerability by sending a large number of connection requests to an affected system. A successful exploit could allow the attacker to exhaust available connection resources, causing Cisco CNC and Cisco NSO to become unresponsive and resulting in a DoS condition for legitimate users and dependent services. A manual reboot of the system is required to recover from this condition.

CVE-2026-20188 References

External References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nso-dos-7Egqyc

CWE Common Weakness Enumeration

CAPEC Common Attack Pattern Enumeration and Classification

• XML Ping of the Death CAPEC-147 An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
• Sustained Client Engagement CAPEC-227 An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.
• Regular Expression Exponential Blowup CAPEC-492 An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.

Other 5 Recently Published CVEs Vulnerabilities

• CVE-2026-8031 – A vulnerability was detected in PicoTronica e-Clinic Healthcare System ECHS 5.7. The affected element is an unknown function of the file /cdemos/ec...
• CVE-2026-8022 – Inappropriate implementation in MHTML in Google Chrome prior to 148.0.7778.96 allowed a remote attacker who convinced a user to engage in specific ...
• CVE-2026-8021 – Script injection in UI in Google Chrome prior to 148.0.7778.96 allowed a remote attacker who convinced a user to engage in specific UI gestures to ...
• CVE-2026-8020 – Uninitialized Use in GPU in Google Chrome on Android prior to 148.0.7778.96 allowed a remote attacker who had compromised the renderer process to o...
• CVE-2026-8019 – Insufficient policy enforcement in WebApp in Google Chrome prior to 148.0.7778.96 allowed a remote attacker to perform UI spoofing via a crafted HT...