Description
Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.



The “quiche_connection_id_iter_next” and “quiche_conn_retired_scid_next” functions would return a pointer to a “ConnectionId” to the applications via function arguments, but the owned “ConnectionId” would be dropped at the end of those functions' scope.



Only applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag.



Impact
If unpatched, an application calling the affected FFI functions will dereference freed memory. The most likely outcome is undefined behavior leading to a process crash (denial of service). Depending on allocator state, the read may also return adjacent heap contents, resulting in limited information disclosure or incorrect connection identifier handling.



Mitigation
Users are requested to upgrade to quiche 0.29.2 which is the earliest version containing the fix for this issue.
Published: 2026-06-19
Score: 5.6 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mh64-ph39-mrc9 Cloudflare Quiche: Use-after-free in connection ID iterator FFI functions
History

Mon, 22 Jun 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 19 Jun 2026 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Cloudflare
Cloudflare quiche
Vendors & Products Cloudflare
Cloudflare quiche

Fri, 19 Jun 2026 11:30:00 +0000

Type Values Removed Values Added
Description Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions. The “quiche_connection_id_iter_next” and “quiche_conn_retired_scid_next” functions would return a pointer to a “ConnectionId” to the applications via function arguments, but the owned “ConnectionId” would be dropped at the end of those functions' scope. Only applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag. Impact If unpatched, an application calling the affected FFI functions will dereference freed memory. The most likely outcome is undefined behavior leading to a process crash (denial of service). Depending on allocator state, the read may also return adjacent heap contents, resulting in limited information disclosure or incorrect connection identifier handling. Mitigation Users are requested to upgrade to quiche 0.29.2 which is the earliest version containing the fix for this issue.
Title Use-after-free in connection ID iterator and FFI functions
Weaknesses CWE-416
References
Metrics cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L'}


Subscriptions

Cloudflare Quiche
cve-icon MITRE

Status: PUBLISHED

Assigner: cloudflare

Published:

Updated: 2026-06-22T15:10:00.033Z

Reserved: 2026-06-10T20:16:34.590Z

Link: CVE-2026-11941

cve-icon Vulnrichment

Updated: 2026-06-22T15:09:56.065Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-19T13:45:05Z

Weaknesses