{"id":"CVE-2026-12708","published":"2026-11-10T14:17:29.980","lastModified":"2026-11-10T14:17:29.980","description":"Summary\n\n\nCloudflare tokio-quiche was found to contain an uncontrolled resource consumption vulnerability in its HTTP/3 DATAGRAM handling. For every previously unseen flow identifier (quarter stream ID) received in a DATAGRAM frame, tokio-quiche creates and retains new, per-flow state. A remote peer can send DATAGRAMs with many distinct identifiers, causing the per-connection flow map and associated channel state to grow without bound.\n\nImpact\n\n\nExploitation can exhaust process memory and cause a denial of service. The vulnerable code is used in both client and server configurations, so either role can be affected by a malicious peer. QUIC DATAGRAM support in tokio-quiche is enabled by default through QuicSettings::enable_dgram; applications can disable it by setting this field to false. The vulnerable HTTP/3 path is reachable only when DATAGRAM support is negotiated with the peer. Core quiche and HTTP/3 deployments without DATAGRAM support are not affected. \n\n\n\n\n\n\nMitigation\n\n\nDisable DATAGRAMs in tokio-quiche’s QuicSettings::enable_dgram.\n\n\n\n\n\n\nRemediation\n\n\nUpgrade to tokio-quiche version 0.23.0 or later. The fixed code creates flow state only for valid DATAGRAM-capable request streams, which are bounded by QUIC’s stream limits. To tolerate packet reordering, servers retain early DATAGRAMs in a bounded, expiring buffer, while clients discard DATAGRAMs for unknown flows.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-401"],"vendors":[],"products":[],"references":[{"url":"https://github.com/cloudflare/quiche/security/advisories/GHSA-wcm9-jv39-r963","tags":[]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-12708","tags":[]}],"exploitRefs":[{"url":"https://github.com/cloudflare/quiche/security/advisories/GHSA-wcm9-jv39-r963","tags":[]}],"hasPoc":true,"ai":null}