{"api_version":"1","generated_at":"2026-06-25T17:31:27+00:00","cve":"CVE-2026-11941","urls":{"html":"https://cve.report/CVE-2026-11941","api":"https://cve.report/api/cve/CVE-2026-11941.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-11941","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-11941"},"summary":{"title":"Use-after-free in connection ID iterator and FFI functions","description":"Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.\n\n\n\nThe “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.\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.","state":"PUBLISHED","assigner":"cloudflare","published_at":"2026-06-19 12:16:26","updated_at":"2026-06-22 17:51:46"},"problem_types":["CWE-416","CWE-416 CWE-416 Use after free"],"metrics":[{"version":"3.1","source":"cna@cloudflare.com","type":"Secondary","score":"5.6","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","baseScore":5.6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"5.6","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","data":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.6,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/cloudflare/quiche/security/advisories/GHSA-mh64-ph39-mrc9","name":"https://github.com/cloudflare/quiche/security/advisories/GHSA-mh64-ph39-mrc9","refsource":"cna@cloudflare.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-11941","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11941","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Cloudflare","product":"Quiche","version":"affected 0.20.0 0.29.1 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"11941","cve":"CVE-2026-11941","epss":"0.001700000","percentile":"0.065830000","score_date":"2026-06-24","updated_at":"2026-06-25 00:05:30"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-11941","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-06-22T15:09:49.880714Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-06-22T15:10:00.033Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","product":"Quiche","repo":"https://github.com/cloudflare/quiche","vendor":"Cloudflare","versions":[{"lessThanOrEqual":"0.29.1","status":"affected","version":"0.20.0","versionType":"semver"}]}],"datePublic":"2026-06-19T09:49:00.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.</p><p>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.</p><p>Only applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag.</p><p><span><b>Impact<br></b></span><span>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.</span></p><p><span><b>Mitigation<br></b></span><span>Users are requested to upgrade to quiche 0.29.2 which is the earliest version containing the fix for this issue.</span></p><p><b></b><br></p><br>"}],"value":"Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.\n\n\n\nThe “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.\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."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.6,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","description":"CWE-416 Use after free","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-06-19T09:55:54.501Z","orgId":"a22f1246-ba21-4bb4-a601-ad51614c1513","shortName":"cloudflare"},"references":[{"url":"https://github.com/cloudflare/quiche/security/advisories/GHSA-mh64-ph39-mrc9"}],"source":{"discovery":"UNKNOWN"},"title":"Use-after-free in connection ID iterator and FFI functions","x_generator":{"engine":"Vulnogram 1.0.2"}}},"cveMetadata":{"assignerOrgId":"a22f1246-ba21-4bb4-a601-ad51614c1513","assignerShortName":"cloudflare","cveId":"CVE-2026-11941","datePublished":"2026-06-19T09:55:54.501Z","dateReserved":"2026-06-10T20:16:34.590Z","dateUpdated":"2026-06-22T15:10:00.033Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-19 12:16:26","lastModifiedDate":"2026-06-22 17:51:46","problem_types":["CWE-416","CWE-416 CWE-416 Use after free"],"metrics":{"cvssMetricV31":[{"source":"cna@cloudflare.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","baseScore":5.6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"LOW"},"exploitabilityScore":2.2,"impactScore":3.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-06-22T15:09:49.880714Z","id":"CVE-2026-11941","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"11941","Ordinal":"1","Title":"Use-after-free in connection ID iterator and FFI functions","CVE":"CVE-2026-11941","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"11941","Ordinal":"1","NoteData":"Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions.\n\n\n\nThe “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.\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.","Type":"Description","Title":"Use-after-free in connection ID iterator and FFI functions"}]}}}