{"id":"CVE-2026-105766","state":"PUBLISHED","title":"Chainguard Academy (edu) Nginx directory redirect downgrades HTTPS requests to HTTP","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.","publishedAt":"2026-10-05T19:45:50.015Z","updatedAt":"2026-10-06T13:44:09.303Z","severity":{"score":2.3,"label":"Low","version":"4.0","vector":"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","source":"chainguard"},"assigner":"chainguard","products":["Chainguard Chainguard Academy (edu)"],"affected":[{"vendor":"Chainguard","product":"Chainguard Academy (edu)","defaultStatus":"unaffected","versions":[{"version":"0b75ff98057f69b044a3e7194e428066ac5ad0d4","status":"affected","lessThan":"93dc0e50739c225f5aee2e803800a47fc0feb906","versionType":"git"}],"repo":"https://github.com/chainguard-dev/edu","modules":["Nginx trailing-slash directory redirect"],"programFiles":["nginx.conf"]}],"references":["https://github.com/chainguard-dev/edu/commit/93dc0e50739c225f5aee2e803800a47fc0feb906","https://github.com/chainguard-dev/edu/pull/3989"],"weaknesses":["CWE-319"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/105xxx/CVE-2026-105766.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-105766","state":"PUBLISHED","datePublished":"2026-10-05T19:45:50.015Z","dateUpdated":"2026-10-06T13:44:09.303Z","assignerShortName":"chainguard","assignerOrgId":"82cea9a6-e9e3-46fe-bdb0-3673de380178","dateReserved":"2026-10-05T19:21:04.930Z"},"containers":{"cna":{"title":"Chainguard Academy (edu) Nginx directory redirect downgrades HTTPS requests to HTTP","descriptions":[{"lang":"en","value":"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. 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The fix is deployed to edu.chainguard.dev; no user action is required.","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>Fixed in commit 93dc0e50739c225f5aee2e803800a47fc0feb906, which hardcodes the <code>https</code> scheme in the redirect. The fix is deployed to <code>edu.chainguard.dev</code>; no user action is required.</p>"}]}],"timeline":[{"time":"2025-07-14T21:34:00.000Z","lang":"en","value":"Vulnerable redirect introduced (chainguard-dev/edu#2411)"},{"time":"2026-09-11T16:16:00.000Z","lang":"en","value":"Fix merged (chainguard-dev/edu#3989)"}],"credits":[{"lang":"en","value":"Matthew Helmke (https://github.com/matthewhelmke)","type":"remediation developer"},{"lang":"en","value":"SunnyR (https://github.com/SunnyR)","type":"coordinator"},{"lang":"en","value":"Chainguard (https://chainguard.dev)","type":"coordinator"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-06T13:43:50.196822Z","id":"CVE-2026-105766","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-06T13:44:09.303Z"}}]}}}