{"id":"GHSA-mhvj-jhpq-885v","title":"blaze: Multiple HTTP/1.1 request-smuggling primitives in blaze's Java wire parser","summary":"blaze: Multiple HTTP/1.1 request-smuggling primitives in blaze's Java wire parser","severity":"high","cvss":7.4,"cwe":["CWE-444"],"vendor":"http4s","product":"org.http4s:http4s-blaze-server_2.13","ecosystem":"maven","affected":["org.http4s:http4s-blaze-server_2.13 <= 0.23.17","org.http4s:blaze-http_2.13 <= 0.23.17","org.http4s:blaze-http_3 <= 0.23.17","org.http4s:blaze-http_3 >= 1.0.0-M1, <= 1.0.0-M41","org.http4s:blaze-http_2.13 >= 1.0.0-M1, <= 1.0.0-M41"],"patched":["org.http4s:http4s-blaze-server_2.13 0.23.18","org.http4s:blaze-http_2.13 0.23.18","org.http4s:blaze-http_3 0.23.18","org.http4s:blaze-http_3 1.0.0-M42","org.http4s:blaze-http_2.13 1.0.0-M42"],"published":"2026-07-24","updated":"2026-07-24","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-mhvj-jhpq-885v","references":[{"url":"https://github.com/http4s/blaze/security/advisories/GHSA-mhvj-jhpq-885v"},{"url":"https://github.com/http4s/blaze/commit/3f7c022e306631b006dcb43a1d7f65c0d1966f17"},{"url":"https://github.com/http4s/blaze/commit/4eec2007806aa9acfefb00ebb636ddc39a147a96"},{"url":"https://github.com/http4s/blaze/commit/927b67753a78c13c4445dac9307f511f5c4878c3"},{"url":"https://github.com/http4s/blaze/commit/a54bc9cd31758335c7f24e29763622fd03fcf734"},{"url":"https://github.com/http4s/blaze/commit/c47d9675f87603f11b32a11d503626bdf9be5c7a"},{"url":"https://github.com/http4s/blaze/commit/e871ebb1d27f50c98fd56988526ce42d0fee74d6"},{"url":"https://github.com/http4s/blaze/releases/tag/v0.23.18"},{"url":"https://github.com/http4s/blaze/releases/tag/v1.0.0-M42"},{"url":"https://github.com/advisories/GHSA-mhvj-jhpq-885v"}],"tags":["ghsa","maven"],"ingestedAt":"2026-07-24T22:40:26.732Z","slug":"GHSA-mhvj-jhpq-885v","body":"## Overview\n\n### Summary\n  Five independent HTTP/1.1 conformance laxities in blaze's hand-written Java parser (`http/src/main/java/org/http4s/blaze/http/parser/`) cause request-boundary disagreement with a stricter intermediary. All are reachable from a default `BlazeServerBuilder` with no non-default configuration.\n\n### Impact\nActual exploitability depends on the fronting proxy — a boundary disagreement requires a *pair* of parsers that disagree. Where the proxy forwards the malformed bytes and derives a different message boundary, the consequences are the standard set: front-end ACL/auth bypass, response-queue poisoning on pooled backend connections, and cache poisoning. Risk concentrates on lenient or legacy intermediaries.\n\n### Workarounds\n  Deploy behind an RFC-strict reverse proxy (nginx, HAProxy, Envoy, ALB) that rejects or re-serializes malformed requests at the edge; this neutralizes most of these for deployments that cannot upgrade immediately.\n\n## Affected packages\n\n- `org.http4s:http4s-blaze-server_2.13 <= 0.23.17`\n- `org.http4s:blaze-http_2.13 <= 0.23.17`\n- `org.http4s:blaze-http_3 <= 0.23.17`\n- `org.http4s:blaze-http_3 >= 1.0.0-M1, <= 1.0.0-M41`\n- `org.http4s:blaze-http_2.13 >= 1.0.0-M1, <= 1.0.0-M41`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `org.http4s:http4s-blaze-server_2.13 0.23.18`\n- `org.http4s:blaze-http_2.13 0.23.18`\n- `org.http4s:blaze-http_3 0.23.18`\n- `org.http4s:blaze-http_3 1.0.0-M42`\n- `org.http4s:blaze-http_2.13 1.0.0-M42`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":40.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}