Cyber Resilience

CVE-2026-55432

Access Control in Coder ≤ 2.29.17

Published
08 July 2026
Modified
08 July 2026
Patch / advisory
CVSS Score v3.1 5.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0018 8th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-55432 is a medium-severity Missing Authorization (CWE-862) vulnerability in Coder Coder. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 8th 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 AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the `CreateSubAgent` RPC did not validate a requested app sharing level against the template's `MaxPortSharingLevel` before persisting workspace apps, letting a workspace…

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owner exceed the administrator's configured maximum. Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2clamps the sub-agent app sharing level to the template's `MaxPortSharingLevel`. As a workaround, disable wildcard app hostnames (`CODER_WILDCARD_ACCESS_URL`) to block subdomain-based app routing.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Missing authorization check (CWE-862) in CreateSubAgent RPC allows workspace owners to exceed MaxPortSharingLevel, enabling unauthorized exposure of workspace apps via subdomain routing. This directly maps to exploitation of a public-facing application (T1190) when CODER_WILDCARD_ACCESS_URL is enabled.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-31681Shared CWE-862
CVE-2023-46309Shared CWE-862
CVE-2025-27296Shared CWE-862
CVE-2025-31691Shared CWE-862
CVE-2025-64356Shared CWE-862
CVE-2025-22318Shared CWE-862
CVE-2025-26956Shared CWE-862
CVE-2025-48916Shared CWE-862
CVE-2025-8285Shared CWE-862
CVE-2025-7772Shared CWE-862

Affected Assets

coder
coder
≤ 2.29.17 · 2.30.0 — 2.32.7 · 2.33.0 — 2.33.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
  • CM-6 Configuration Settings
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Enforces the template-defined MaxPortSharingLevel on every CreateSubAgent call so a workspace owner cannot exceed the administrator-configured sharing limit.

prevent

Limits the privileges granted to workspace-owner accounts so they cannot create sub-agent apps with sharing levels higher than the template permits.

prevent

Ensures the MaxPortSharingLevel setting in the template baseline is applied and cannot be bypassed by sub-agent registration.

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.

PR.AA-05 full match
prevents

Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.

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.

prevents

Requiring authentication and credentials before any access occurs eliminates the absence of authorization checks that would otherwise allow an unauthenticated actor to reach protected resources.

prevents

Requiring formal authorization of every access request before rights are granted ensures that checks for required permissions are performed, preventing missing authorization checks from being introduced.

prevents

Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.

mitigates

Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.

detects

By requiring competent outsiders to verify that every function enforces the need-to-know principle, the control lowers the likelihood that missing authorization checks persist undetected.

prevents

Defining authorization responsibilities and reviewing risk-treatment progress throughout the project lifecycle catches missing authorization checks before the system is deployed.

References