CVE-2025-68131

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-12-31 02:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 09:58 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-12-31 02:15 UTC

Last modified

2026-06-17 09:58 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-212

Record status

Analyzed

Affected

• Agronholm cbor2 < 5.8.0

Attack profile CVSS 4.0 · 5.5

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

None

Confidentiality

Low

Integrity

None

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-68131.md and follow it. Check whether this project is affected by CVE-2025-68131. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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