GHSA-36xw-fx78-c5r4: github.com/containerd/containerd (CVE-2020-15257)

Package	Ecosystem	Affected	Fixed in
github.com/containerd/containerd	Go	<1.3.9 \|\| >=1.4.0, <1.4.3	1.3.9, 1.4.3

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

containerd versions before 1.3.9 and from 1.4.0 before 1.4.3 are affected. Containers running in the same network namespace as the containerd-shim, such as host network containers, can connect to the shim's abstract Unix socket and cause new processes to run with elevated privileges, if they have an effective UID of 0 but reduced privileges otherwise. Upgrade to containerd 1.3.9 or 1.4.3, then stop and restart containers started with an older shim, since they stay vulnerable after upgrading. Avoid running untrusted containers in the host network namespace with UID 0.

Written 6 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.2	Medium	3.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.031, the 87th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:46 UTC First seen by agentprime
31 Oct 2026, 14:46 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.