← Vulnerability feed

Vulnerability record · CVE-2026-55430 · published 8 July 2026

CVE-2026-55430: Coder insufficient verification of data authenticity vulnerability

Coder · Coder

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 workspace app proxy resolves the target app from `httpapi.RequestHost()` which prefers the `X-Forwarded-Host` header over the real `Host` header. No middleware strips `X-Forwarded-Host` before routing and the header is not browser-forbidden so client-side JavaScript can set it on `fetch()` calls. Practical exploitation requires subdomain app routing (wildcard hostname) enabled, a victim who visits the attacker's shared app and a deployment whose upstream proxy does not strip `X-Forwarded-Host`. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 trusts `X-Forwarded-Host` only from configured trusted proxies and otherwise resolves the routing host from the verified request host. As a workaround, place an upstream reverse proxy that strips or overwrites `X-Forwarded-Host` on untrusted requests.

6.8 CVSS 3.1 Medium EPSS 0.21% · top 90.2% CWE-345 · Insufficient verification of data authenticityCWE-441 · CWE-441
6.8CVSS 3.1 base score
0.21%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References
8 Jul 2026Last modified by NVD

Description

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 workspace app proxy resolves the target app from `httpapi.RequestHost()` which prefers the `X-Forwarded-Host` header over the real `Host` header. No middleware strips `X-Forwarded-Host` before routing and the header is not browser-forbidden so client-side JavaScript can set it on `fetch()` calls. Practical exploitation requires subdomain app routing (wildcard hostname) enabled, a victim who visits the attacker's shared app and a deployment whose upstream proxy does not strip `X-Forwarded-Host`. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 trusts `X-Forwarded-Host` only from configured trusted proxies and otherwise resolves the routing host from the verified request host. As a workaround, place an upstream reverse proxy that strips or overwrites `X-Forwarded-Host` on untrusted requests.

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/coder/coder/pull/26204 Issue TrackingPatch
https://github.com/coder/coder/releases/tag/v2.29.17 Release Notes
https://github.com/coder/coder/releases/tag/v2.32.7 Release Notes
https://github.com/coder/coder/releases/tag/v2.33.8 Release Notes
https://github.com/coder/coder/releases/tag/v2.34.2 Release Notes
https://github.com/coder/coder/security/advisories/GHSA-5g4w-3vw9-478w PatchVendor Advisory

Track CVE-2026-55430 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.1CVE-2026-46354Coder improper verification of cryptographic signature vulnerabilityCoder allows organizations to provision remote development environments via Terraform. In versions prior tp 2.24.5, 2.29.13, 2.30.8, 2.31.12, 2.32.2,…EPSS 0.32%8.8CVE-2026-44454Coder os command injection vulnerabilityCoder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7 and 2.30.2, the `dotfiles` registry m…EPSS 2.6%8.7CVE-2026-55429Coder insecure direct object reference vulnerabilityCoder 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, `UpsertW…EPSS 0.51%8.3CVE-2026-55427Coder injection vulnerabilityCoder 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, `coder c…EPSS 0.47%8.2CVE-2026-55428Coder improper authorization vulnerabilityCoder 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 tail…EPSS 0.40%8.2CVE-2024-27918Coder improper input validation vulnerabilityCoder allows oragnizations to provision remote development environments via Terraform. Prior to versions 2.6.1, 2.7.3, and 2.8.4, a vulnerability in …EPSS 0.97%8.1CVE-2025-58437Coder insufficient session expiration vulnerabilityCoder allows organizations to provision remote development environments via Terraform. In versions 2.22.0 through 2.24.3, 2.25.0 and 2.25.1, Coder ca…EPSS 0.38%7.4CVE-2026-55436Coder improper certificate validation vulnerabilityCoder allows organizations to provision remote development environments via Terraform. Starting in version 2.30.0 and prior to versions 2.32.7, 2.33.…EPSS 0.26%

Source: NIST National Vulnerability Database (record CVE-2026-55430), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.