CVE-2026-23490 is a high-severity vulnerability affecting the pyasn1 library used in Debian systems. The vulnerability is classified as a Denial-of-Service (DoS) issue, specifically caused by malformed RELATIVE-OID inputs with excessive continuation octets. This can lead to memory exhaustion, which can disrupt service availability for applications relying on this library.
The CVSS score for this vulnerability is 7.5, indicating a high level of risk. Organizations using affected versions of Debian and pyasn1 should prioritize remediation efforts. The urgency to address this issue is high, as it can significantly impact system availability.
As of now, no known exploits are publicly available, and the vulnerability has not been actively exploited in the wild. However, the potential for exploitation exists, and organizations should not delay in applying the necessary updates.
Organizations should prioritize patching immediately to mitigate the risks associated with this vulnerability. The fixed version, 0.6.2, is available and should be deployed as soon as possible.
Vulnerability Details
The pyasn1 library is a popular ASN.1 library for Python. The vulnerability identified in CVE-2026-23490 allows an attacker to send malformed data that exhausts the memory resources of the application utilizing the library. This vulnerability is fixed in version 0.6.2 of pyasn1.
The vulnerability has been classified under CWE-770, which pertains to allocation of resources without limits. The CVSS vector for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, indicating that it requires no privileges or user interaction to exploit.
The vulnerability was published on January 16, 2026, and the remediation has been clearly outlined in the official release notes for version 0.6.2.
Technical Analysis
The root cause of CVE-2026-23490 is attributed to improper handling of input data within the pyasn1 library. When the library processes a RELATIVE-OID with excessive continuation octets, it leads to memory exhaustion. This vulnerability can be exploited over a network, making it particularly concerning for systems exposed to the internet.
The attack complexity is considered low, as no special privileges are required to trigger this vulnerability. Furthermore, there is no need for user interaction, which increases the risk for organizations relying on the affected software.
The vulnerability impacts availability significantly, as successful exploitation can render the application unusable by exhausting available memory. However, there are no impacts on confidentiality or integrity.
Risk & Impact Analysis
Risk to organizations includes potential downtime or service disruption due to memory exhaustion. Given the widespread use of Debian systems and the pyasn1 library, the blast radius of this vulnerability could be extensive, affecting multiple applications and services within an organization.
The urgency assessment based on the CVSS score indicates that organizations should address this vulnerability in their priority patch cycle. Failure to remediate could result in significant operational impacts, especially for services that rely heavily on the affected library.
Organizations are encouraged to evaluate their deployment of Debian and pyasn1 and consider the potential risks associated with not patching to version 0.6.2.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected version of pyasn1 is prior to 0.6.2. For Debian Linux, the affected version is 11.0. Organizations should ensure that they upgrade to the latest version to mitigate this vulnerability.
Mitigation & Remediation
To mitigate the risks associated with CVE-2026-23490, organizations should upgrade to pyasn1 version 0.6.2 or later. If updating is not feasible, consider implementing network controls to limit exposure to untrusted inputs.
For further information on securing your applications, organizations may refer to our application security assessment services.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor application logs for unusual memory usage patterns or crashes that could indicate a DoS attack. Additionally, review network traffic for malformed ASN.1 inputs.
AppSecure Threat Intelligence Insight
CVE-2026-23490 highlights the importance of maintaining updated libraries and dependencies to prevent potential vulnerabilities. This incident serves as a reminder to organizations to adopt a proactive approach towards security and vulnerability management.
To further enhance security, organizations should engage in regular penetration testing to identify and remediate similar vulnerabilities.
Additionally, organizations should consider establishing a comprehensive vulnerability management program that includes regular assessments and monitoring of dependencies.
In conclusion, staying informed about potential vulnerabilities and maintaining an updated security posture is essential for organizations to safeguard their assets.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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