CVE-2026-26210

CriticalPublic PoCRCE

Published: 23 April 2026

Published

23 April 2026

Modified

05 May 2026

KEV Added

—

Patch

—

CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0008 22.5th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26210 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Kvcache-Ai Ktransformers. 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 22.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SC-7 (Boundary Protection) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

Requires validation of incoming messages to the ZMQ socket before deserialization, directly preventing execution of crafted pickle payloads.

SI-2 Flaw Remediation good match

prevent

Mandates identification, reporting, and correction of the unsafe deserialization flaw, enabling application of the available vendor patch.

SC-7 Boundary Protection good match

prevent

Monitors and controls network communications at boundaries to block unauthorized access to the ZMQ ROUTER socket bound to all interfaces.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1059.006 Python Execution

Adversaries may abuse Python commands and scripts for execution.

attack.mitre.org →

Why these techniques?

Unsafe pickle deserialization on unauthenticated, publicly bound ZMQ RPC socket directly enables remote arbitrary code execution (T1190 Exploit Public-Facing Application) via Python interpreter (T1059.006 Python).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

KTransformers through 0.5.3 contains an unsafe deserialization vulnerability in the balance_serve backend mode where the scheduler RPC server binds a ZMQ ROUTER socket to all interfaces with no authentication and deserializes incoming messages using pickle.loads() without validation. Attackers can send…

a crafted pickle payload to the exposed ZMQ socket to execute arbitrary code on the server with the privileges of the ktransformers process.

Deeper analysisAI

CVE-2026-26210 is an unsafe deserialization vulnerability (CWE-502) in KTransformers versions through 0.5.3. The issue resides in the balance_serve backend mode, where the scheduler RPC server binds a ZMQ ROUTER socket to all interfaces without authentication and deserializes incoming messages using the pickle.loads() function without any validation. Published on 2026-04-23, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), marking it as critical.

Remote attackers require no privileges or user interaction to exploit the vulnerability over the network. By sending a crafted pickle payload to the exposed ZMQ socket, they can achieve arbitrary code execution on the server with the privileges of the ktransformers process, potentially leading to full compromise of the host.

Advisories and a patch are detailed in referenced sources, including a GitHub pull request at https://github.com/kvcache-ai/ktransformers/pull/1944, a technical post at https://chocapikk.com/posts/2026/ktransformers-pickle-rce/, and a VulnCheck advisory at https://www.vulncheck.com/advisories/ktransformers-unsafe-deserialization-rce-via-balance-serve.