CVE-2026-42503
Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-42503 is a high-severity Binding to an Unrestricted IP Address (CWE-1327) vulnerability in Go (inferred from references). Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-27872
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Establishes the most restrictive configuration settings, which would require binding only to specific addresses rather than 0.0.0.0.
Enforces approved information flow policies that would disallow unrestricted remote bindings.
Enforces least functionality by prohibiting unnecessary network exposure such as unrestricted listening addresses.
Requires control of communications at external and key internal interfaces, preventing binding that accepts traffic from any source.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Configuration management enforces restricted bind addresses, covering the weakness completely but only one aspect of overall hardening.
Network protection controls directly prevent exposure via unrestricted binds while fixing the weakness addresses only one vector of unauthorized access.
Documenting authorized network flows informs correct bind decisions and reduces the chance of 0.0.0.0 usage.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security of network services includes hardening service bindings to prevent exposure on all interfaces.
Secure architecture principles discourage exposing services on all interfaces, though the control is broader than this single weakness.
Network security controls directly require restricting listening interfaces to specific addresses rather than 0.0.0.0.
Network segregation can limit the blast radius of an unrestricted binding but does not prevent the binding itself.
Secure coding guidance can catch hard-coded 0.0.0.0 bindings during development but is not the primary mitigation.