CVE-2026-49950: Xorbits Xoscar 0.11.2 Unauthenticated Deserialization RCE via Actor Pool

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-13 · updated 2026-10-16
Weakness: CWE-502

Description

Xorbits Xoscar through 0.11.2 contains an unauthenticated deserialization vulnerability that allows remote attackers to execute arbitrary code by sending crafted data over the actor-pool TCP channel. Attackers can exploit SocketChannel.recv() passing unvalidated data to cloudpickle.loads(), which triggers pickle __reduce__ gadget execution before message type validation, achieving remote code execution as the server process which commonly runs as root on GPU nodes.

Affected products

xorbitsai xoscar: from 0.1.0 through 0.11.2

References

https://github.com/xorbitsai/xoscar/blob/v0.11.2/python/xoscar/backends/communication/socket.py#L99-L104
https://github.com/xorbitsai/xoscar/blob/v0.11.2/python/xoscar/serialization/core.pyx#L260
https://www.vulncheck.com/advisories/xorbits-xoscar-unauthenticated-deserialization-rce-via-actor-pool
https://www.vulncheck.com/blog/xorbits-xoscar-unauth-cloudpickle-rce

Get alerted when CVE-2026-49950 or the next vulnerability affects your stack