{"id":"CVE-2026-55877","aliases":["EUVD-2026-42444","GHSA-6v8j-33hc-mv84"],"status":"published","title":"Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00338,"percentile":0.27447,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2026-06-19T21:42:15Z","modified":"2026-10-28T02:31:06Z","fixes":[{"ecosystem":"Packagist","package":"symfony/ux-icons","fixed_in":["2.36.1","3.2.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"symfony/ux-icons","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.17.0"},{"fixed":"2.36.1"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/ux-icons","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.2.0"}]}]},{"source":"osv","ecosystem":"Packagist","package":"symfony/ux-icons","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.17.0"},{"fixed":"2.36.1"}]}],"versions":["v2.17.0","v2.18.0","v2.18.1","v2.19.0","v2.20.0","v2.21.0","v2.22.0","v2.22.1","v2.23.0","v2.24.0","v2.25.0","v2.26.0","v2.27.0","v2.28.0","v2.28.2","v2.29.0","v2.29.2","v2.30.0","v2.31.0","v2.32.0","v2.33.0","v2.34.0","v2.35.0","v2.36.0"]},{"source":"osv","ecosystem":"Packagist","package":"symfony/ux-icons","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.2.0"}]}],"versions":["v3.0.0","v3.1.0"]}],"products":[{"vendor":"symfony","product":"ux"}],"references":[{"url":"https://github.com/symfony/ux/security/advisories/GHSA-6v8j-33hc-mv84","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://github.com/symfony/ux/commit/3a4964ec3700f0af4e13f7bfbf8bb3174c3e79d1","tags":["x_refsource_MISC","Patch","fix"]},{"url":"https://github.com/symfony/ux/releases/tag/v2.36.1","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://github.com/symfony/ux/releases/tag/v3.2.0","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/ux-icons/CVE-2026-55877.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-6v8j-33hc-mv84"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55877.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55877","tags":["advisory"]},{"url":"https://github.com/symfony/ux","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-55877","title":"Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.","status":"published","published":"2026-07-08T21:32:37.407Z","modified":"2026-07-09T14:40:25.026Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:12.260247Z"}],"euvd":[{"id":"EUVD-2026-42444","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.","status":"published","published":"2026-07-08T21:32:37Z","modified":"2026-07-09T14:40:25Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T18:20:04.126011Z"}],"ghsa":[{"id":"GHSA-6v8j-33hc-mv84","title":"symfony/ux-icons: XSS via unsanitized SVG content in local files and Iconify on-demand responses","description":"### Description\n\nThe `ux_icon()` Twig function is marked `is_safe=['html']`, so Twig never escapes its output. `Icon::toHtml()` inlines the SVG source verbatim into the page. Browsers execute `\u003cscript\u003e` elements and `on*` event-handler attributes found inside inline SVG, making any unsanitized icon a vector for cross-site scripting.\n\nTwo code paths were affected. In the local file path, `Icon::fromFile()` only stripped `\u003cscript\u003e` elements that were direct children of `\u003csvg\u003e`, leaving nested scripts and all `on*` attributes untouched despite a code comment claiming broader protection. In the Iconify on-demand path (enabled by default), the remote JSON `body` field was wrapped into an `Icon` object with no sanitization at all. Concrete attack vectors include a malicious SVG icon pack from a third-party theme or downloaded icon set, or a controlled Iconify endpoint configured via `iconify.endpoint` (including a poisoned cache).\n\n### Resolution\n\nIntroducing an `IconFactory` that centralizes sanitization across every icon source before an `Icon` object is created. The sanitizer removes script-capable elements (`script`, `foreignObject`, `iframe`, `object`, `embed`), SMIL animations targeting `on*`, `href`, or `xlink:href` attributes, CDATA sections, processing instructions, all `on*` attributes, and `javascript:`, `vbscript:`, and `data:text/html` URL schemes. \n`\u003cstyle\u003e` elements are kept for theming but have any handlers stripped. Icons that contain none of these constructs are byte-for-byte identical after sanitization. \n\n### Credits\n\nSymfony would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.","status":"published","published":"2026-06-19T21:42:15Z","modified":"2026-06-19T21:42:15Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:40:31.656952Z"}],"nvd":[{"id":"CVE-2026-55877","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.","status":"published","published":"2026-07-08T22:17:15.92Z","modified":"2026-10-25T17:10:00.197Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:28.4135Z"}],"osv":[{"id":"CVE-2026-55877","title":"Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses","description":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.","status":"published","published":"2026-07-08T21:32:37.407Z","modified":"2026-10-28T02:31:06.075325561Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:11.609219Z"},{"id":"GHSA-6v8j-33hc-mv84","title":"symfony/ux-icons: XSS via unsanitized SVG content in local files and Iconify on-demand responses","description":"### Description\n\nThe `ux_icon()` Twig function is marked `is_safe=['html']`, so Twig never escapes its output. `Icon::toHtml()` inlines the SVG source verbatim into the page. Browsers execute `\u003cscript\u003e` elements and `on*` event-handler attributes found inside inline SVG, making any unsanitized icon a vector for cross-site scripting.\n\nTwo code paths were affected. In the local file path, `Icon::fromFile()` only stripped `\u003cscript\u003e` elements that were direct children of `\u003csvg\u003e`, leaving nested scripts and all `on*` attributes untouched despite a code comment claiming broader protection. In the Iconify on-demand path (enabled by default), the remote JSON `body` field was wrapped into an `Icon` object with no sanitization at all. Concrete attack vectors include a malicious SVG icon pack from a third-party theme or downloaded icon set, or a controlled Iconify endpoint configured via `iconify.endpoint` (including a poisoned cache).\n\n### Resolution\n\nIntroducing an `IconFactory` that centralizes sanitization across every icon source before an `Icon` object is created. The sanitizer removes script-capable elements (`script`, `foreignObject`, `iframe`, `object`, `embed`), SMIL animations targeting `on*`, `href`, or `xlink:href` attributes, CDATA sections, processing instructions, all `on*` attributes, and `javascript:`, `vbscript:`, and `data:text/html` URL schemes. \n`\u003cstyle\u003e` elements are kept for theming but have any handlers stripped. Icons that contain none of these constructs are byte-for-byte identical after sanitization. \n\n### Credits\n\nSymfony would like to thank Pascal Cescon for reporting the issue and Hugo Alliaume for providing the fix.","status":"published","published":"2026-06-19T21:42:15Z","modified":"2026-09-10T03:51:08.052739946Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:39.965326Z"}]}}