CVE-2026-12523

Summary Cloudflare quiche's HTTP/3 layer was discovered to be vulnerable to resource exhaustion (i.e., memory) by means of specially crafted HTTP/3 frames. Impact HTTP/3 defines multiple frame types to support HTTP message exchanges and connection management. Each frame has a length and a payload whose length depends on the frame type. quiche was found to be vulnerable when parsing some frame types to pre-allocating memory based on the declared length. An attacker would not need to send the number of declared bytes to trigger this issue. In addition, quiche was found to not apply QPACK decompression limits correctly. This could allow an attacker to send specially crafted HEADERS frames that would cause more memory commitment than otherwise advertised by MAX_FIELD_SECTION_SIZE (configured by set_max_field_section_size()). Mitigation: * Users are requested to upgrade to quiche 0.29.3 which is the earliest version containing the fix for this issue. Credits: Disclosed responsibly by Sébastien Féry

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/cloudflare/quiche/security/advisories/GHSA-4fgf-9xrr-88gf

Configurations

No configuration.

History

15 Jul 2026, 18:16

Type	Values Removed	Values Added
CWE		CWE-400

14 Jul 2026, 16:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-14 16:16

Updated : 2026-07-15 18:16

NVD link : CVE-2026-12523

Mitre link : CVE-2026-12523

CVE.ORG link : CVE-2026-12523

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

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