{"id":"CVE-2022-31103","aliases":["EUVD-2022-5983","GHSA-7r3r-gq8p-v9jj"],"status":"published","title":"Improper handling of CSS at-rules in lettersanitizer","description":"lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.01526,"percentile":0.74865,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-754"],"published":"2022-06-23T17:48:19Z","modified":"2026-10-28T02:31:04Z","fixes":[{"ecosystem":"npm","package":"lettersanitizer","fixed_in":["1.0.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"lettersanitizer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.2"}]}]},{"source":"osv","ecosystem":"npm","package":"lettersanitizer","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.0.2"}]}]}],"products":[{"vendor":"lettersanitizer_project","product":"lettersanitizer"},{"vendor":"mat-sz","product":"lettersanitizer"}],"references":[{"url":"https://github.com/mat-sz/lettersanitizer/security/advisories/GHSA-7r3r-gq8p-v9jj","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/mat-sz/react-letter/issues/17","tags":["x_refsource_MISC","x_transferred","Issue Tracking","Third Party Advisory","report","web"]},{"url":"https://github.com/mat-sz/lettersanitizer/commit/96d3dfe2ef0465d47324ed4d13e91ba0816a173f","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2022-31103","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7r3r-gq8p-v9jj"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/31xxx/CVE-2022-31103.json","tags":["advisory"]},{"url":"https://github.com/mat-sz/lettersanitizer","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2022-31103","title":"Improper handling of CSS at-rules in lettersanitizer","description":"lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.","status":"published","published":"2022-06-27T22:20:16Z","modified":"2025-04-23T18:06:15.856Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T14:34:35.279735Z"}],"euvd":[{"id":"EUVD-2022-5983","description":"lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.","status":"published","published":"2022-06-27T22:20:16Z","modified":"2025-04-23T18:06:15Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T20:52:09.919052Z"}],"ghsa":[{"id":"GHSA-7r3r-gq8p-v9jj","title":"Improper handling of CSS at-rules in lettersanitizer","description":"### Impact\n\nAll versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`.\n\nThis package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk.\n\n### Patches\n\nThe problem has been patched in version 1.0.2.\n\n### Workarounds\n\nThere is no workaround besides upgrading.\n\n### References\n\nThe issue was originally reported in the react-letter repository: https://github.com/mat-sz/react-letter/issues/17\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [lettersanitizer](https://github.com/mat-sz/lettersanitizer/issues)\n* Email me at [contact@matsz.dev](mailto:contact@matsz.dev)\n","status":"published","published":"2022-06-23T17:48:19Z","modified":"2023-01-27T05:04:35Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T14:36:20.985872Z"}],"nvd":[{"id":"CVE-2022-31103","description":"lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.","status":"published","published":"2022-06-27T23:15:08.17Z","modified":"2026-06-17T04:44:48.233Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T14:07:22.966735Z"}],"osv":[{"id":"CVE-2022-31103","title":"Improper handling of CSS at-rules in lettersanitizer","description":"lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.","status":"published","published":"2022-06-27T22:20:16Z","modified":"2026-10-28T02:31:04.572621399Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T15:44:25.516981Z"},{"id":"GHSA-7r3r-gq8p-v9jj","title":"Improper handling of CSS at-rules in lettersanitizer","description":"### Impact\n\nAll versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`.\n\nThis package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk.\n\n### Patches\n\nThe problem has been patched in version 1.0.2.\n\n### Workarounds\n\nThere is no workaround besides upgrading.\n\n### References\n\nThe issue was originally reported in the react-letter repository: https://github.com/mat-sz/react-letter/issues/17\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [lettersanitizer](https://github.com/mat-sz/lettersanitizer/issues)\n* Email me at [contact@matsz.dev](mailto:contact@matsz.dev)\n","status":"published","published":"2022-06-23T17:48:19Z","modified":"2023-11-08T04:09:26.205914Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T15:46:41.349637Z"}]}}