CVE-2026-88975
CVE-2026-88975 updated by NVD
Summary
Http4s is a Scala interface for HTTP services. Prior to 0.23.37 and 1.0.0-M48, Ember’s HTTP/2 read loop parses a frame’s 24-bit declared length but waits to buffer the entire payload before comparing it with SETTINGS_MAX_FRAME_SIZE. An unauthenticated peer can declare a payload near 16 MiB on a connection where Ember advertised 16 KiB and either complete or slowly stream it, causing up to 1024-fold memory amplification per connection before processFrame can reject the frame. The shared H2Connection.readLoop affects withHttp2 servers and clients, while HTTP/2-disabled configurations are unaffected, and the patch rejects oversized frames before buffering their payloads. This issue is fixed in versions 0.23.37 and 1.0.0-M48.
Affected packages
| Ecosystem | Package | Affected versions | Fixed versions |
|---|---|---|---|
| Maven | org.http4s:http4s-ember-core_2.12 | — | 0.23.37 |
| Maven | org.http4s:http4s-ember-core_2.13 | — | 0.23.37, 1.0.0-M48 |
| Maven | org.http4s:http4s-ember-core_3 | — | 0.23.37, 1.0.0-M48 |
Remediation: Upgrade to 0.23.37 or later.
References
Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.
Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.
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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.