Chainguard Academy (edu) Nginx directory redirect downgrades HTTPS requests to HTTP
Summary
| CVE | CVE-2026-105766 |
|---|---|
| State | PUBLISHED |
| Assigner | chainguard |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-05 20:17:20 UTC |
| Updated | 2026-10-05 20:17:20 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 2.3 LOW from 82cea9a6-e9e3-46fe-bdb0-3673de380178
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-319 | CWE-319 CWE-319 Cleartext Transmission of Sensitive Information
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 82cea9a6-e9e3-46fe-bdb0-3673de380178 | Secondary | 2.3 | LOW | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 2.3 | LOW | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N |
| 3.1 | 82cea9a6-e9e3-46fe-bdb0-3673de380178 | Secondary | 3.1 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N |
| 3.1 | CNA | CVSS | 3.1 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Chainguard | Chainguard Academy Edu | affected 0b75ff98057f69b044a3e7194e428066ac5ad0d4 93dc0e50739c225f5aee2e803800a47fc0feb906 git | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/chainguard-dev/edu/commit/93dc0e50739c225f5aee2e803800a47fc0f... | 82cea9a6-e9e3-46fe-bdb0-3673de380178 | github.com | |
| github.com/chainguard-dev/edu/pull/3989 | 82cea9a6-e9e3-46fe-bdb0-3673de380178 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Matthew Helmke (https://github.com/matthewhelmke) (en)
CNA: SunnyR (https://github.com/SunnyR) (en)
CNA: Chainguard (https://chainguard.dev) (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2025-07-14T21:34:00.000Z | Vulnerable redirect introduced (chainguard-dev/edu#2411) |
| CNA | 2026-09-11T16:16:00.000Z | Fix merged (chainguard-dev/edu#3989) |
Solutions
CNA: Fixed in commit 93dc0e50739c225f5aee2e803800a47fc0feb906, which hardcodes the https scheme in the redirect. The fix is deployed to edu.chainguard.dev; no user action is required.