CVE-2026-42503
Accidental binding to INADDR_ANY might lead to RCE in golang.org/x/tools/gopls
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.
INFO
Published Date :
May 6, 2026, 5:16 p.m.
Last Modified :
Sept. 18, 2026, 3:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Do not use -port or -listen flags in production.
- Configure firewall to restrict network access to gopls.
- Use gopls only on trusted networks.
- Update gopls to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42503.
| URL | Resource |
|---|---|
| https://go.dev/cl/774381 | Patch |
| https://go.dev/issue/79211 | Issue Tracking Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42503 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42503
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42503 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42503 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:golang:gopls:*:*:*:*:*:go:*:* versions up to (excluding) 0.22.0 Added Reference Type Go Project: https://go.dev/cl/774381 Types: Patch Added Reference Type Go Project: https://go.dev/issue/79211 Types: Issue Tracking, Vendor Advisory -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'golang.org/x/tools', 'product': 'golang.org/x/tools/gopls', 'versions': [{'status': 'affected', 'version': '0.0.0', 'lessThan': '0.22.0', 'versionType': 'semver'}], 'packageName': 'golang.org/x/tools/gopls', 'collectionURL': 'https://pkg.go.dev', 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-42503', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-06T00:00:00+00:00'} -
New CVE Received by [email protected]
May. 06, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-1327 Added Reference https://go.dev/cl/774381 Added Reference https://go.dev/issue/79211 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 06, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H