CVE-2026-12708
Received
Received - Intake
BaseFortify
Vulnerability report for CVE-2026-12708, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-10
Last updated on: 2026-11-10
Assigner: Cloudflare, Inc.
Description
Description
Summary
Cloudflare 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.
Impact
Exploitation 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.
Mitigation
Disable DATAGRAMs in tokio-quiche’s QuicSettings::enable_dgram.
Remediation
Upgrade 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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Cloudflare | tokio-quiche | From 0.0.1 (inc) to 0.20.1 (inc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-401 | The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse. |
