CVE-2026-33320 identifies a medium-severity vulnerability in Dasel, a command-line tool and library developed by TomWright for querying, modifying, and transforming data structures. This vulnerability allows, starting from version 3.0.0 and before version 3.3.1, an attacker who can supply YAML for processing to trigger extreme CPU and memory consumption. The issue is rooted in the library's own `UnmarshalYAML` implementation, which manually resolves alias nodes without any expansion budget, bypassing the built-in alias expansion limit in go-yaml v4.
The vulnerability has been assigned a CVSS score of 6.2, indicating its medium severity. The potential risk to organizations includes denial-of-service conditions due to excessive resource consumption when processing malicious YAML inputs. As a result, organizations utilizing the affected versions of Dasel should schedule remediation promptly to prevent service disruptions.
It is important to note that there are currently no known exploits for this vulnerability. However, the absence of a public proof of concept does not negate the severity of the issue, and organizations should not underestimate the potential for exploitation given the nature of the vulnerability.
Organizations should prioritize patching immediately, as version 3.3.2 of Dasel contains a fix for this vulnerability. Regular updates and monitoring of software dependencies are crucial in maintaining a secure environment.
Vulnerability Details
The CVE-2026-33320 vulnerability is officially described as follows: Dasel is a command-line tool and library for querying, modifying, and transforming data structures. Starting in version 3.0.0 and prior to version 3.3.1, Dasel's YAML reader allows an attacker who can supply YAML for processing to trigger extreme CPU and memory consumption. The issue is in the library's own `UnmarshalYAML` implementation, which manually resolves alias nodes by recursively following `yaml.Node.Alias` pointers without any expansion budget, bypassing go-yaml v4's built-in alias expansion limit. Version 3.3.2 contains a patch for the issue.
The CVSS score of 6.2 indicates medium severity, with a high availability impact and no confidentiality or integrity impact. The attack vector is local, requiring no privileges or user interaction.
Technical Analysis
The root cause of this vulnerability lies in the way Dasel processes YAML alias nodes. The library's implementation does not enforce limits on the depth of alias resolution, which could lead to excessive resource consumption, ultimately causing a denial-of-service condition. The attack vector is local, meaning an attacker must have access to the system where Dasel is running.
The attack complexity is low, as it does not require any special conditions or privileges. No user interaction is needed to exploit this vulnerability, which further increases its risk profile. The impact on availability is high, as the system could become unresponsive due to resource exhaustion.
Risk & Impact Analysis
Risk to organizations includes potential denial-of-service attacks through resource exhaustion when processing malicious YAML. The blast radius can be significant if Dasel is used in critical systems or applications, potentially affecting availability across services that depend on it.
Given the CVSS score of 6.2, organizations should address this vulnerability in their priority patch cycle. Regular assessments of software dependencies and their configurations can significantly mitigate the risk associated with such vulnerabilities.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch (3.3.2) are affected. Specifically, versions 3.0.0 to 3.3.1 of Dasel should be considered vulnerable.
Mitigation & Remediation
To mitigate the risks associated with CVE-2026-33320, organizations should upgrade to Dasel version 3.3.2 or later. If a patch cannot be applied immediately, consider implementing the following workarounds:
1. Limit the processing of YAML input to trusted sources only.
2. Monitor resource utilization for unusual spikes that may indicate exploitation attempts.
Organizations should also consider engaging in penetration testing to assess their security posture and identify potential vulnerabilities.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for the following indicators:
1. Unusual patterns of CPU and memory consumption during YAML processing.
2. Errors related to resource allocation or system performance.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-33320 highlights the risks associated with resource management in software libraries. Organizations must remain vigilant regarding the dependencies they utilize and the potential for vulnerabilities that could lead to denial-of-service conditions.
This vulnerability represents a trend of increasing complexity in software libraries, necessitating thorough testing and validation processes. Security teams should prioritize regular assessments of their software environments to identify and mitigate risks.
For further insights, organizations can explore resources on penetration testing methodology, the importance of vulnerability management programs, and the role of continuous security testing in reducing exposure to such vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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