CVE-2026-26210: KTransformers Unsafe Deserialization RCE via balance_serve
KTransformers through 0.5.3 contains an unsafe deserialization flaw in balance_serve mode, where an unauthenticated ZMQ socket is reachable on all interfaces. The record describes possible arbitrary code execution with the privileges of the ktransformers process and a critical CVSS 9.8 score. No KEV listing or confirmed active exploitation appears in the sources consulted.
Overview
KTransformers through 0.5.3 has an unsafe deserialization flaw (CWE-502) in its balance_serve backend mode. According to the record, the scheduler RPC server binds a ZMQ ROUTER socket to all interfaces without authentication and passes incoming messages to pickle.loads() without validation.
Impact
- According to the record, a party that can reach the socket may execute arbitrary code with the privileges of the ktransformers process.
- VulnCheck assigns a CVSS base score of 9.8 (critical). A second score of 9.3 from VulnCheck is listed under a different CVSS version.
- SSVC lists technical impact as total and automatable as yes.
Affected products and versions
- Kvcache-ai Ktransformers, all versions up to and including 0.5.3.
- The record gives no earlier boundary, so the start of the affected range is unknown.
Exploitation status
- The record shows this CVE is not listed in CISA KEV, so no active exploitation is confirmed by that source.
- SSVC exploitation is rated poc, and one referenced third-party write-up is tagged as exploit material. Public proof-of-concept availability should be treated as likely.
Remediation and mitigation
- The record references a patch in pull request 1944 of the KTransformers repository and a third-party mitigation article. The record gives no fixed release version, so check the upstream repository for the current status.
- Do not expose the scheduler RPC port to untrusted networks. Restrict it with host or network firewalls and bind it to loopback where the deployment allows.
- Run the service with least privilege and isolate it from sensitive data and credentials.
Detection guidance
- Inventory hosts running balance_serve mode and identify which ones listen on non-loopback interfaces.
- Review network logs for unexpected inbound connections to the ZMQ port used by the scheduler.
- Monitor the ktransformers process for unexpected child processes or outbound connections.
Limitations of the available information
- The record does not state the default port, the first affected version, or any fixed version.
- The record does not confirm the contents of the patch or whether the pull request has been merged.
- The EPSS probability is 0.01044 with percentile 0.63853, dated 2026-10-23 in the record.
Frequently asked questions
Which KTransformers versions are affected?
According to the record, KTransformers versions up to and including 0.5.3 are affected. The record does not state the earliest affected version.
Is this vulnerability being actively exploited?
The record shows it is not listed in CISA KEV, so no active exploitation is confirmed by that source. The SSVC exploitation field is rated poc, which indicates proof-of-concept activity is possible.
What should administrators do first?
Restrict network access to the scheduler RPC port, avoid exposing it to untrusted networks, and check the upstream repository for a fixed release, since the record gives no fixed version.
This analysis was drafted with AI assistance from verified source data and automatically checked against it.