{"id":"CVE-2026-27492","aliases":["EUVD-2026-7708","GHSA-49pc-8936-wvfp"],"status":"published","title":"Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused","description":"Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected. This issue has been fixed in version 1.5.1.","severity":{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00186,"percentile":0.08333,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-488"],"published":"2026-02-20T21:14:49Z","modified":"2026-10-28T02:30:34Z","fixes":[{"ecosystem":"npm","package":"lettermint","fixed_in":["1.5.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"lettermint","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.1"}]}]},{"source":"osv","ecosystem":"npm","package":"lettermint","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.5.1"}]}]}],"products":[{"vendor":"lettermint","product":"lettermint"},{"vendor":"lettermint","product":"lettermint-node"}],"references":[{"url":"https://github.com/lettermint/lettermint-node/security/advisories/GHSA-49pc-8936-wvfp","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/lettermint/lettermint-node/commit/24a17acbc2429c5eb30391f9df3dc0ea7aaf4de1","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://github.com/lettermint/lettermint-node/blob/main/CHANGELOG.md#151-2026-02-20","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27492","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-49pc-8936-wvfp"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27492.json","tags":["advisory"]},{"url":"https://github.com/lettermint/lettermint-node","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-27492","title":"Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused","description":"Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected. This issue has been fixed in version 1.5.1.","status":"published","published":"2026-02-21T10:16:03.913Z","modified":"2026-02-24T18:08:44.011Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-488"],"updated_at":"2026-11-02T14:19:48.826324Z"}],"euvd":[{"id":"EUVD-2026-7708","description":"Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected. This issue has been fixed in version 1.5.1.","status":"published","published":"2026-02-21T10:16:03Z","modified":"2026-02-24T18:08:44Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T19:48:29.958768Z"}],"ghsa":[{"id":"GHSA-49pc-8936-wvfp","title":"Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused","description":"### Impact\nEmail properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected.\n\n### Patches\nYes, the issue has been patched. Users should upgrade to v1.5.1 or later.\n\n### Workarounds\nIf upgrading immediately is not possible, instantiate a new client for each send:\n```js\nconst client = new Lettermint({ apiKey: process.env.LETTERMINT_API_KEY });\nawait client.email.to('...').subject('...').html('...').send();\n```\n\nThis ensures no state is carried over between sends.","status":"published","published":"2026-02-20T21:14:49Z","modified":"2026-02-23T22:30:21Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-488"],"updated_at":"2026-11-02T14:39:26.881079Z"}],"nvd":[{"id":"CVE-2026-27492","description":"Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected. This issue has been fixed in version 1.5.1.","status":"published","published":"2026-02-21T11:15:57.287Z","modified":"2026-06-17T10:27:14.857Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-488"],"updated_at":"2026-11-02T14:12:06.63895Z"}],"osv":[{"id":"CVE-2026-27492","title":"Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused","description":"Lettermint Node.js SDK is the official Node.js SDK for Lettermint. In versions 1.5.0 and below, email properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected. This issue has been fixed in version 1.5.1.","status":"published","published":"2026-02-21T10:16:03.913Z","modified":"2026-10-28T02:30:34.168334996Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-488"],"updated_at":"2026-11-02T15:45:00.180685Z"},{"id":"GHSA-49pc-8936-wvfp","title":"Lettermint Node.js SDK leaks email properties to unintended recipients when client instance is reused","description":"### Impact\nEmail properties (such as to, subject, html, text, and attachments) are not reset between sends when a single client instance is reused across multiple .send() calls. This can cause properties from a previous send to leak into a subsequent one, potentially delivering content or recipient addresses to unintended parties. Applications sending emails to different recipients in sequence — such as transactional flows like password resets or notifications — are affected.\n\n### Patches\nYes, the issue has been patched. Users should upgrade to v1.5.1 or later.\n\n### Workarounds\nIf upgrading immediately is not possible, instantiate a new client for each send:\n```js\nconst client = new Lettermint({ apiKey: process.env.LETTERMINT_API_KEY });\nawait client.email.to('...').subject('...').html('...').send();\n```\n\nThis ensures no state is carried over between sends.","status":"published","published":"2026-02-20T21:14:49Z","modified":"2026-02-23T22:53:00.479537Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-488"],"updated_at":"2026-11-02T15:46:36.782754Z"}]}}