Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2025-68131

Severity CVSS v4.0:
MEDIUM
Type:
Unavailable / Other
Publication date:
31/12/2025
Last modified:
31/12/2025

Description

cbor2 provides encoding and decoding for the Concise Binary Object Representation (CBOR) serialization format. Starting in version 3.0.0 and prior to version 5.8.0, whhen a CBORDecoder instance is reused across multiple decode operations, values marked with the shareable tag (28) persist in memory and can be accessed by subsequent CBOR messages using the sharedref tag (29). This allows an attacker-controlled message to read data from previously decoded messages if the decoder is reused across trust boundaries. Version 5.8.0 patches the issue.

Impact

Vector 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P CVSS v4.0 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): Low
Integrity (VI): None
Availability (VA): Low
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None
Exploit Maturity (E): POC

Base Score 4.0
5.50
Severity 4.0
MEDIUM

References to Advisories, Solutions, and Tools