Http4s: FollowRedirect middleware leaks credentials over https->http same-authority redirect
cve-program · CVE-2026-69212
PublishedHttp4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The FollowRedirect client middleware strips Authorization and Cookie headers only when a redirect changes authority, but authority comparison excludes the URI scheme. A same-authority redirect from HTTPS to HTTP therefore preserves credentials and transmits them over a plaintext connection. An attacker who can induce the downgrade and observe the network can capture those sensitive headers from applications using FollowRedirect. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
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cve-program · CVE-2026-69212
PublishedHttp4s: FollowRedirect middleware leaks credentials over https->http same-authority redirect
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The FollowRedirect client middleware strips Authorization and Cookie headers only when a redirect changes authority, but authority comparison excludes the URI scheme. A same-authority redirect from HTTPS to HTTP therefore preserves credentials and transmits them over a plaintext connection. An attacker who can induce the downgrade and observe the network can capture those sensitive headers from applications using FollowRedirect. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
- Source published
- 15 Sep 2026 19:09:57 UTC
- Source modified
- 15 Sep 2026 19:30:41 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
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CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N