CVE-2026-31048
Published: 13 April 2026
Summary
CVE-2026-31048 is a critical-severity Code Injection (CWE-94) vulnerability. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 25.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly requires timely remediation of known flaws like CVE-2026-31048 in Pyro's pickle protocol to prevent arbitrary code execution.
Mandates validation of information inputs such as crafted pickled string messages to block code injection attacks.
Enforces secure configuration settings for Pyro to disable or restrict the vulnerable pickle protocol as outlined in security documentation.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated RCE via malicious pickle deserialization in network-exposed Pyro server directly enables T1190 (Exploit Public-Facing Application) for initial access and T1059.006 (Python) for arbitrary code execution.
NVD Description
An issue in the <code>pickle</code> protocol of Pyro v3.x allows attackers to execute arbitrary code via supplying a crafted pickled string message.
Deeper analysisAI
CVE-2026-31048 is a critical vulnerability in the pickle protocol implementation of Pyro v3.x, a Python remote object communication library. The flaw allows attackers to execute arbitrary code by supplying a crafted pickled string message, classified under CWE-94 (code injection). It has a CVSS v3.1 base score of 9.8, reflecting its network accessibility, low attack complexity, lack of required privileges or user interaction, and high impact on confidentiality, integrity, and availability.
Remote, unauthenticated attackers can exploit this vulnerability over the network by sending a maliciously crafted pickled message to a Pyro v3.x server. Successful exploitation leads to arbitrary code execution on the target system with the privileges of the Pyro process, potentially enabling full system compromise.
Mitigation details are outlined in the GitHub Security Advisory GHSA-7625-w9h5-83rv, the affected code in Pyro/protocol.py (lines 672-711), and Pyro3 security documentation (section 9, lines 341-346), which likely discuss secure configuration or upgrades to address the pickle protocol risks. The vulnerability was published on 2026-04-13.
Details
- CWE(s)