🛡️ CVE-2026-12523 — quiche

🟠 CVSS 7.5 — High ✅ No Known Exploit CWE-400 NVD
7.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Weakness class

CVE-2026-12523 is classified as CWE-400: Uncontrolled Resource Consumption. A request can consume memory, CPU or storage without limit, exhausting capacity for everyone else.

Affected software

CVE-2026-12523 is recorded against 1 package.

  • quiche (from 0.1.0 up to 0.29.3)

Timeline and source

Published on 14 July 2026 and last revised on 6 August 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com

Details

Severity HIGH
CVSS Score 7.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE CWE-400
Public Exploit ✅ No
Source NVD
Published 2026-07-14
Updated 2026-08-11
Modified 2026-08-06
Fix URL N/A

Affected Packages

Software From version Fixed in
quiche 0.1.0 0.29.3

Similar Threats

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