Cloudflare quiche up to 0.29.2 PathEvent path_event_next resource consumption

Summaryinfo

A vulnerability classified as problematic was found in Cloudflare quiche up to 0.29.2. This affects the function path_event_next of the component PathEvent. The manipulation results in resource consumption. This vulnerability is identified as CVE-2026-12707. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Cloudflare quiche up to 0.29.2. Affected is the function path_event_next of the component PathEvent. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-12707 since 06/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 0.29.3 eliminates this vulnerability.

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Productinfo

Type

• Cloud Software

Vendor

• Cloudflare

Name

• quiche

Version

• 0.29.0
• 0.29.1
• 0.29.2

Website

• Product: https://github.com/cloudflare/quiche/

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