Vulnerability in Chainguard Academy (Edu)

CVE-2026-105766

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-105766?
CVE-2026-105766 is a low-severity vulnerability in Chainguard Academy (Edu), classified under Cleartext Transmission of Sensitive Information. CVSS score: 3.1/10. Published 2026-10-05.
How severe is CVE-2026-105766?
Low severity. CVSS v3 base score is 3.1 out of 10.