CVE-2026-11941
Cloudflare Quiche: Use-after-free in connection ID iterator FFI functions
Description
### 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.
How to fix CVE-2026-11941
To remediate CVE-2026-11941, upgrade the affected package to a fixed version below.
- —upgrade to 0.29.2 or later
Is CVE-2026-11941 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 0.20.0, < 0.29.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.6 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L |