---
id: CVE-2026-11941
title: 'Cloudflare Quiche: Use-after-free in connection ID iterator FFI functions'
summary: 'Cloudflare Quiche: Use-after-free in connection ID iterator FFI functions'
severity: medium
cvss: 5.6
cwe:
  - CWE-416
vendor: quiche
product: quiche
ecosystem: rust
affected:
  - 'quiche >= 0.20.0, < 0.29.2'
patched:
  - quiche 0.29.2
published: '2026-06-19'
updated: '2026-06-19'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-mh64-ph39-mrc9'
references:
  - url: >-
      https://github.com/cloudflare/quiche/security/advisories/GHSA-mh64-ph39-mrc9
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-11941'
  - url: 'https://github.com/advisories/GHSA-mh64-ph39-mrc9'
tags:
  - ghsa
  - rust
epss: 0.00251
epssPercentile: 0.14579
ingestedAt: '2026-06-22T13:35:24.216Z'
---

## Overview

### Impact

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 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.

quiche 0.29.2 is the earliest version containing the fix for this issue.

## Affected packages

- `quiche >= 0.20.0, < 0.29.2`

## Remediation

Upgrade to a patched release:

- `quiche 0.29.2`