{"id":"CVE-2026-49215","aliases":["EUVD-2026-45218","GHSA-4m4j-hmqq-3gxm"],"status":"published","title":"Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.22.0 until 2.36.0 and 3.1.0, Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest() gates #[LiveAction] invocations on Accept: application/vnd.live-component+html, but the Accept header is CORS-safelisted and cross-origin fetch() can set it without preflight, allowing forged cross-origin #[LiveAction] requests against a victim session when applications use SameSite=None, credentials: 'include', a permissive cookie policy, or a same-origin pivot. This issue is fixed in versions 2.36.0 and 3.1.0.","severity":{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00177,"percentile":0.07327,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-352"],"published":"2026-06-19T19:35:01Z","modified":"2026-10-28T02:31:03Z","fixes":[{"ecosystem":"Packagist","package":"symfony/ux-live-component","fixed_in":["2.36.0","3.1.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"symfony/ux-live-component","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.22.0"},{"fixed":"2.36.0"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/ux-live-component","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.1.0"}]}]},{"source":"osv","ecosystem":"Packagist","package":"symfony/ux-live-component","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.22.0"},{"fixed":"2.36.0"}]}],"versions":["v2.22.0","v2.22.1","v2.23.0","v2.24.0","v2.25.0","v2.25.1","v2.25.2","v2.26.0","v2.26.1","v2.27.0","v2.28.0","v2.28.1","v2.28.2","v2.29.0","v2.29.1","v2.29.2","v2.30.0","v2.31.0","v2.32.0","v2.33.0","v2.34.0","v2.35.0"]},{"source":"osv","ecosystem":"Packagist","package":"symfony/ux-live-component","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.1.0"}]}],"versions":["v3.0.0"]}],"products":[{"vendor":"symfony","product":"ux"}],"references":[{"url":"https://github.com/symfony/ux/security/advisories/GHSA-4m4j-hmqq-3gxm","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://github.com/symfony/ux/commit/aed7493db2b4b7bf1f9c79b33cda544f06904b27","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://github.com/symfony/ux/releases/tag/v2.36.0","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://github.com/symfony/ux/releases/tag/v3.1.0","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/ux-live-component/CVE-2026-49215.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-4m4j-hmqq-3gxm"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49215.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49215","tags":["advisory"]},{"url":"https://github.com/symfony/ux","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-49215","title":"Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.22.0 until 2.36.0 and 3.1.0, Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest() gates #[LiveAction] invocations on Accept: application/vnd.live-component+html, but the Accept header is CORS-safelisted and cross-origin fetch() can set it without preflight, allowing forged cross-origin #[LiveAction] requests against a victim session when applications use SameSite=None, credentials: 'include', a permissive cookie policy, or a same-origin pivot. This issue is fixed in versions 2.36.0 and 3.1.0.","status":"published","published":"2026-07-17T16:16:42.126Z","modified":"2026-07-17T18:05:15.93Z","cvss":[{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low","assessor":"cna"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T13:35:10.963527Z"}],"euvd":[{"id":"EUVD-2026-45218","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.22.0 until 2.36.0 and 3.1.0, Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest() gates #[LiveAction] invocations on Accept: application/vnd.live-component+html, but the Accept header is CORS-safelisted and cross-origin fetch() can set it without preflight, allowing forged cross-origin #[LiveAction] requests against a victim session when applications use SameSite=None, credentials: 'include', a permissive cookie policy, or a same-origin pivot. This issue is fixed in versions 2.36.0 and 3.1.0.","status":"published","published":"2026-07-17T16:16:42Z","modified":"2026-07-17T18:05:15Z","cvss":[{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low"}],"updated_at":"2026-11-02T18:19:50.451546Z"}],"ghsa":[{"id":"GHSA-4m4j-hmqq-3gxm","title":"symfony/ux-live-component: CSRF Protection Bypass — Accept Header is CORS-Safelisted","description":"### Description\n\nWhen using `symfony/ux-live-component`, methods annotated with `#[LiveAction]` are invokable from the browser and mutate server-side state via AJAX. `Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest()` gated these invocations on the presence of `Accept: application/vnd.live-component+html`, with a code comment stating that this acted as a CSRF protection.\n\nThe `Accept` header is a [CORS-safelisted request header](https://fetch.spec.whatwg.org/#cors-safelisted-request-header), so a cross-origin `fetch()` can set it without triggering a preflight. The header therefore provided no CSRF protection. Any `#[LiveAction]` could be forged cross-origin against a victim's session.\n\nIn practice the attack is mitigated by `SameSite=Lax` session cookies (Symfony's default), but applications using `SameSite=None`, `credentials: 'include'` with a permissive cookie policy, or that have been pivoted from another same-origin vector remained exposed.\n\n### Resolution\n\n`isLiveComponentRequest()` now additionally requires the request header `X-Requested-With: XMLHttpRequest`. This header is **not** CORS-safelisted, so the browser issues a preflight `OPTIONS` request for any cross-origin attempt; Symfony does not advertise CORS for LiveComponent endpoints, the preflight fails, and the real request is blocked before it reaches the application. The bundled Stimulus client already sends `X-Requested-With` on every LiveComponent request (`RequestBuilder.ts`), so standard usage is unaffected. Cross-origin callers must add `X-Requested-With` to their CORS `Access-Control-Allow-Headers` allow-list.\n\nThe patch for this issue is available [here](https://github.com/symfony/ux/commit/aed7493db2b4b7bf1f9c79b33cda544f06904b27) for branch 2.x (and forward-ported to 3.x).\n\n### Credits\n\nSymfony would like to thank Anthropic (via Project Glasswing) for reporting the issue and Hugo Alliaume for providing the fix.","status":"published","published":"2026-06-19T19:35:01Z","modified":"2026-06-19T19:35:01Z","cvss":[{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T14:40:30.53004Z"}],"nvd":[{"id":"CVE-2026-49215","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.22.0 until 2.36.0 and 3.1.0, Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest() gates #[LiveAction] invocations on Accept: application/vnd.live-component+html, but the Accept header is CORS-safelisted and cross-origin fetch() can set it without preflight, allowing forged cross-origin #[LiveAction] requests against a victim session when applications use SameSite=None, credentials: 'include', a permissive cookie policy, or a same-origin pivot. This issue is fixed in versions 2.36.0 and 3.1.0.","status":"published","published":"2026-07-17T17:17:16.06Z","modified":"2026-10-24T20:10:00.137Z","cvss":[{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low","assessor":"secondary"},{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T14:12:30.250437Z"}],"osv":[{"id":"CVE-2026-49215","title":"Symfony UX: CSRF Protection Bypass in symfony/ux-live-component — Accept Header is CORS-Safelisted","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.22.0 until 2.36.0 and 3.1.0, Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest() gates #[LiveAction] invocations on Accept: application/vnd.live-component+html, but the Accept header is CORS-safelisted and cross-origin fetch() can set it without preflight, allowing forged cross-origin #[LiveAction] requests against a victim session when applications use SameSite=None, credentials: 'include', a permissive cookie policy, or a same-origin pivot. This issue is fixed in versions 2.36.0 and 3.1.0.","status":"published","published":"2026-07-17T16:16:42.126Z","modified":"2026-10-28T02:31:03.192435103Z","cvss":[{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T15:45:07.060148Z"},{"id":"GHSA-4m4j-hmqq-3gxm","title":"symfony/ux-live-component: CSRF Protection Bypass — Accept Header is CORS-Safelisted","description":"### Description\n\nWhen using `symfony/ux-live-component`, methods annotated with `#[LiveAction]` are invokable from the browser and mutate server-side state via AJAX. `Symfony\\UX\\LiveComponent\\EventListener\\LiveComponentSubscriber::isLiveComponentRequest()` gated these invocations on the presence of `Accept: application/vnd.live-component+html`, with a code comment stating that this acted as a CSRF protection.\n\nThe `Accept` header is a [CORS-safelisted request header](https://fetch.spec.whatwg.org/#cors-safelisted-request-header), so a cross-origin `fetch()` can set it without triggering a preflight. The header therefore provided no CSRF protection. Any `#[LiveAction]` could be forged cross-origin against a victim's session.\n\nIn practice the attack is mitigated by `SameSite=Lax` session cookies (Symfony's default), but applications using `SameSite=None`, `credentials: 'include'` with a permissive cookie policy, or that have been pivoted from another same-origin vector remained exposed.\n\n### Resolution\n\n`isLiveComponentRequest()` now additionally requires the request header `X-Requested-With: XMLHttpRequest`. This header is **not** CORS-safelisted, so the browser issues a preflight `OPTIONS` request for any cross-origin attempt; Symfony does not advertise CORS for LiveComponent endpoints, the preflight fails, and the real request is blocked before it reaches the application. The bundled Stimulus client already sends `X-Requested-With` on every LiveComponent request (`RequestBuilder.ts`), so standard usage is unaffected. Cross-origin callers must add `X-Requested-With` to their CORS `Access-Control-Allow-Headers` allow-list.\n\nThe patch for this issue is available [here](https://github.com/symfony/ux/commit/aed7493db2b4b7bf1f9c79b33cda544f06904b27) for branch 2.x (and forward-ported to 3.x).\n\n### Credits\n\nSymfony would like to thank Anthropic (via Project Glasswing) for reporting the issue and Hugo Alliaume for providing the fix.","status":"published","published":"2026-06-19T19:35:01Z","modified":"2026-09-10T03:51:07.83064468Z","cvss":[{"version":"4.0","score":2.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","level":"low"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T15:46:37.148947Z"}]}}