CVE-2026-31048Network attack vector

Unauthenticated code execution via unsafe pickle deserialization

Published Apr 13, 2026 · Updated Apr 13, 2026

Unsafe deserialization in Pyro 3.16 and earlier allows remote attackers to execute arbitrary code through crafted network messages. During request handling, the protocol handler passes unauthenticated serialized message data to pickle.loads(), permitting attacker-selected object reconstruction and reduce callables. Any attacker able to reach a Pyro 3.x server can run code with the server process's privileges; no authentication or user interaction is required.

CVSS severity9.8
Critical
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in Pyro 3.16 and earlier allows remote attackers to execute arbitrary code through crafted network messages. During request handling, the protocol handler passes unauthenticated serialized message data to pickle.loads(), permitting attacker-selected object reconstruction and reduce callables. Any attacker able to reach a Pyro 3.x server can run code with the server process's privileges; no authentication or user interaction is required.

The record

CVE
CVE-2026-31048
Published
Apr 13, 2026
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-502, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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