{"id":"GHSA-j8rw-jp99-435v","summary":"Forge: TLS client crash on a handshake record received without a session","details":"### Summary\nA `forge.tls` client throws an uncaught `TypeError` from `connection.process()` when it receives a ServerHello while it has no session: after a `close_notify` alert or a call to `close()`, or before `handshake()` is called. A malicious server or an on-path attacker can use this to terminate a Node.js process. Fixed in node-forge 1.4.3.\n\n### Details\n`tls.handleHandshake()` in `lib/tls.js` updates the handshake digests with `c.session.md5.update(bytes)` before it calls the message handler. A client creates its session in `handshake()`, and `c.reset()` sets it to `null` when the connection is closed. Closing doesn't set the fail flag, and the client goes back to expecting a ServerHello, so a Handshake record received afterwards still reaches `handleHandshake()`, which throws `TypeError: Cannot read properties of null (reading 'md5')`.\n\nThis happens:\n- after the server sends a `close_notify` alert (at any alert level);\n- after the application calls `close()`;\n- before the application calls `handshake()`.\n\nThe exception propagates out of `connection.process()`. Applications that pass socket data to `process()` from a `data` event handler without catching exceptions, as in the README example, terminate. After a reset the connection uses no encryption, so an on-path attacker can inject the records even when the real server is honest.\n\nServers are not affected: a server creates its session when it receives a ClientHello.\n\nThe fix handles these records like other unexpected records on a closed client: they are ignored.\n\n#### Patches\nFixed in node-forge 1.4.3.\n\n#### Workarounds\nCatch exceptions thrown by `connection.process()` and close the socket, or stop passing socket data to `process()` once the `closed` callback has been called and until `handshake()` is called again.\n\n#### Resources\n- RFC 5246, section 7.2.1 (Closure Alerts): https://www.rfc-editor.org/rfc/rfc5246#section-7.2.1\n- Related: GHSA-525v-9gp9-w22h (another TLS client `TypeError`, fixed in 1.4.1): https://github.com/digitalbazaar/forge/security/advisories/GHSA-525v-9gp9-w22h\n\n#### Severity\nCVSS 3.1: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H (5.9, Moderate)\nCVSS 4.0 (informational): CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N (8.2)\nCVSS 4.0 has no counterpart to 3.1's AC:H beyond AT:P and scores this higher; the severity rating follows CVSS 3.1.\n\n#### Credits\nReported by @manus-use.\n\n### Proof of concept\n    var c = forge.tls.createConnection({server: false, ...});\n    c.handshake();\n    // warning close_notify alert, then an empty ServerHello, in separate\n    // process() calls\n    c.process(forge.util.hexToBytes('15030100020100'));\n    c.process(forge.util.hexToBytes('160301000402000000'));\n    // \u003c= 1.4.2: TypeError: Cannot read properties of null (reading 'md5')\n    // 1.4.3: the record is ignored\n\nThe reporter's PoC is in tests/pocs/ghsa-j8rw-jp99-435v.js, and regression tests are in tests/unit/tls.js.\n\n### Impact\nApplications that use `forge.tls` as a client and pass data from a network socket to `connection.process()` are affected. The server they connect to, or an on-path attacker, can make `process()` throw; if the application doesn't catch it, the Node.js process terminates, dropping all its connections. Servers built on `forge.tls` are not affected. There is no confidentiality or integrity impact.","aliases":["CVE-2026-125334"],"modified":"2026-11-10T21:30:04.008068866Z","published":"2026-11-10T21:14:26Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-11-10T21:14:26Z","nvd_published_at":null,"cwe_ids":["CWE-476"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/digitalbazaar/forge/security/advisories/GHSA-j8rw-jp99-435v"},{"type":"WEB","url":"https://github.com/digitalbazaar/forge/pull/1169"},{"type":"WEB","url":"https://github.com/digitalbazaar/forge/commit/2cfaeb516cb3d4aff1c0569d39394df41c5cb17c"},{"type":"PACKAGE","url":"https://github.com/digitalbazaar/forge"},{"type":"WEB","url":"https://github.com/digitalbazaar/forge/releases/tag/v1.4.3"}],"affected":[{"package":{"name":"node-forge","ecosystem":"npm","purl":"pkg:npm/node-forge"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.4.3"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 1.4.2","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/11/GHSA-j8rw-jp99-435v/GHSA-j8rw-jp99-435v.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}