Chainguard Academy Trailing-Slash Directory Redirect nginx.conf scheme cleartext transmission

Summaryinfo

A vulnerability was found in Chainguard Academy and classified as problematic. Affected by this issue is some unknown functionality of the file nginx.conf of the component Trailing-Slash Directory Redirect. Executing a manipulation of the argument scheme can lead to cleartext transmission. This vulnerability appears as CVE-2026-105766. The attack may be performed from remote. There is no available exploit. This product operates as a managed service, which prevents users from maintaining vulnerability countermeasures themselves. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability has been found in Chainguard Academy (the affected version is unknown) and classified as problematic. This vulnerability affects an unknown code of the file nginx.conf of the component Trailing-Slash Directory Redirect. The manipulation of the argument scheme with an unknown input leads to a cleartext transmission vulnerability. The CWE definition for the vulnerability is CWE-319. The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors. As an impact it is known to affect confidentiality. CVE summarizes:

Use of the backend-facing $scheme variable in the trailing-slash directory redirect in nginx.conf of Chainguard Academy (edu) from commit 0b75ff98057f69b044a3e7194e428066ac5ad0d4 before commit 93dc0e50739c225f5aee2e803800a47fc0feb906 allows an on-path network attacker to read or modify documentation content served to a victim via an HTTPS request for a slashless directory path, because TLS terminates at the load balancer in front of Nginx and the resulting 301 response redirects the client to a plaintext http:// URL. Browsers that ship the HSTS preload list are not affected, because the .dev top-level domain is preloaded; clients that do not enforce HSTS, such as command-line HTTP clients and scripts that follow redirects, are affected.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-105766 since 10/05/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1040.

Applying the patch 93dc0e50739c225f5aee2e803800a47fc0feb906 is able to eliminate this problem.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Chainguard

Name

• Academy

Managed Service

• yes

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• 🔒

CPE 2.2info

• 🔒

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Once again VulDB remains the best source for vulnerability data.

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