Vulnerability · Published Oct 5, 2026 · Assigned by chainguard

CVE-2026-105766Chainguard Academy (edu) Nginx directory redirect downgrades HTTPS requests to HTTP

Low 3.1

In plain English

A low-severity security flaw in Chainguard Academy (edu) from Chainguard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).

Severity (CVSS 3.1)3.1Low

Exploit odds (30 days)0.1%top 98.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
Chainguard	Chainguard Academy (edu)	0b75ff98057f69b044a3e7194e428066ac5ad0d4 – before 93dc0e50739c225f5aee2e803800a47fc0feb906

Weakness: CWE-319 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

References

Fix commit 93dc0e5 patch
chainguard-dev/edu#3989 patch