CVE-2026-11941 (GCVE-0-2026-11941)
Vulnerability from cvelistv5 – Published: 2026-06-19 09:55 – Updated: 2026-06-19 09:55
VLAI
Title
Use-after-free in connection ID iterator and FFI functions
Summary
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.
Severity
5.6 (Medium)
CWE
- CWE-416 - Use after free
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Cloudflare | Quiche |
Affected:
0.20.0 , ≤ 0.29.1
(semver)
|
Date Public
2026-06-19 09:49
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"value": "Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.\n\n\n\nThe \u201cquiche_connection_id_iter_next\u201d and \u201cquiche_conn_retired_scid_next\u201d functions would return a pointer to a \u201cConnectionId\u201d to the applications via function arguments, but the owned \u201cConnectionId\u201d would be dropped at the end of those functions\u0027 scope.\n\n\n\nOnly applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag.\n\n\n\nImpact\nIf 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.\n\n\n\nMitigation\nUsers are requested to upgrade to quiche 0.29.2 which is the earliest version containing the fix for this issue."
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"url": "https://github.com/cloudflare/quiche/security/advisories/GHSA-mh64-ph39-mrc9"
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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