GHSA-mh64-ph39-mrc9 — medium GitHub Advisory (CVE-2026-11941) in rust/quiche

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.

Basic information

Type: reviewed
Severity: medium
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2026-06-19 22:10:29 UTC
Updated: 2026-06-19 22:10:30 UTC
GitHub reviewed: 2026-06-19 22:10:29 UTC
NVD published: 2026-06-19

CVSS Scores

Base score	Version	Severity	Vector
5.6	3.1	—	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

Type	Value
GHSA	GHSA-mh64-ph39-mrc9 ↗
CVE	CVE-2026-11941 ↗

CWEs

CWE id	Name
CWE-416	Use After Free

Credits

LPardue (remediation_developer)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
rust	quiche	>= 0.20.0, < 0.29.2	0.29.2	—

Cloudflare Quiche: Use-after-free in connection ID iterator FFI functions