Uncontrolled Recursion in CBOR2 - #VU165940
Published: November 11, 2026
Vulnerability identifier: #VU165940
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service by terminating the Python process.
The vulnerability exists due to uncontrolled recursion in cbor2.dumps() when encoding deeply nested Python containers. A remote attacker can supply deeply nested data to an application that serializes attacker-influenced objects to exhaust the native stack and trigger a process-terminating SIGSEGV instead of a catchable Python exception.
Affected software
CBOR2
Remediation
Install security update from vendor's website.
CBOR2 - update to 6.1.5