CVE-2026-12707

HighCVSS 7.5

Published: 14/07/2026(UTC)Updated: 14/07/2026(UTC)Translated: 15/07/2026(UTC)NVD NIST

Summary

Cloudflare quiche was found vulnerable to memory resource exhaustion due to unbounded queuing of post-handshake client migration events. An attacker can exploit rapid source address migration to cause unbounded queuing of PathEvent::ReusedSourceConnectionId events, even if active connection migration is disabled.

Risk Assessment

The organization is at risk of a Denial of Service (DoS) attack via memory exhaustion, potentially leading to unavailability of services using quiche.

Recommendation

Upgrade quiche to version 0.29.3 or later immediately. As a workaround, applications can call path_event_next() to drain the PathEvent collection.

Other vulnerabilities in quiche

CVE-2026-12523High
Cloudflare quiche's HTTP/3 layer is vulnerable to resource exhaustion (memory) via specially crafted HTTP/3 frames. Pre-allocation of memory based on declared frame length can be triggered without sending the full payload. Additionally, incorrect QPACK decompression limits allow memory commitment beyond advertised MAX_FIELD_SECTION_SIZE.

Original NVD description (English source)

Summary Cloudflare quiche was discovered to be vulnerable to memory resource exhaustion due to unbounded queuing of post-handshake client migration events. Impact quiche supports the connection migration features described in Section 9 of RFC 9000, which allows a single QUIC connection to survive changes in the network path. Although quiche implements the protections described in Section 9.3 of RFC 9000 to limit server state commitment, it was discovered that the collection of PathEvents, intended to be consumed by applications via the path_event_next() function, was not bounded. Once the QUIC handshake completed, a peer could exploit rapid source address migration in order to cause unbounded queuing of the PathEvent::ReusedSourceConnectionId type. Servers are vulnerable even if active connection migration is disabled. Mitigation: * Applications can call path_event_next() to drain the PathEvent collection, mitigating the attack. * Users are requested to upgrade to quiche 0.29.3 which is the earliest version that prevents excessive queueing of PathEvent::ReusedSourceConnectionId.