CVE-2026-42503: Accidental binding to INADDR_ANY might lead to RCE in golang.org/x/tools/gopls

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-06 · updated 2026-10-26
Weakness: CWE-1327

Description

gopls by default communicates via pipe. However, -port and -listen flags are supported as means of debugging. If -listen is given a value without an explicit host (e.g. :8080), or -port is used, gopls will listen on 0.0.0.0. As a result, users might inadvertently cause gopls to bind 0.0.0.0. This can allow a malicious party on the same network to execute code arbitrarily via gopls.

Affected products

golang.org/x/tools/gopls: before 0.22.0 — fixed in 0.22.0

How to fix

Upgrade to a fixed version: golang.org/x/tools/gopls 0.22.0. Check the vendor advisory for mitigations.

References

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