{"items":[{"id":"NVI-00010567","kind":"vulnerability","title":"Nodemailer: Quadratic (O(n^2)) SMTP client reply parsing lets a malicious server or MITM cause a pre-auth remote denial of service","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4g23-2xm8-66gc","CVE-2026-110872"],"plain_summary":"GitHub lists this reviewed advisory for nodemailer. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-45ba386d5eb278648ce871f4415e8d3a"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 10.0.10 for nodemailer. Confirm the publisher’s latest guidance.","source_ids":["sr-d7bfc797a4cb342bbc09755281d921ab"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-27T15:04:35.000Z","value":"5.9 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-45ba386d5eb278648ce871f4415e8d3a"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-45ba386d5eb278648ce871f4415e8d3a","url":"https://github.com/advisories/GHSA-4g23-2xm8-66gc","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4g23-2xm8-66gc","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:06:46.371Z"},{"id":"sr-d7bfc797a4cb342bbc09755281d921ab","url":"https://github.com/advisories/GHSA-4g23-2xm8-66gc","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-4g23-2xm8-66gc","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-11-03T02:27:49.579Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-45ba386d5eb278648ce871f4415e8d3a"],"technology":"nodemailer","known_exclusions":[],"conditions_summary":"## Summary\n\nThe SMTP client response parser reassembles multiline server replies by appending each continuation line onto a single response-queue entry and re-testing whether that entry is still a partial (continuation) reply on every line. The partial-response test runs `str.slice(str.lastIndexOf('\\n') + 1)` on the growing entry, which forces a full flatten of the entire accumulated string on each line. A malicious or compromised SMTP server (or an on-path attacker on a plaintext or pre-STARTTLS hop) that streams continuation lines and never sends a completion line drives O(n^2) CPU on the single-threaded Node.js event loop before any authentication, freezing the whole process for an attacker-controlled duration.\n\n## Root Cause\n\nThe invariant that a server cannot cause superlinear client-side work while a reply is being reassembled is violated. In `src/smtp-connection/index.ts`, `_onData` splits inbound bytes into lines and, while the last queued entry is a continuation reply, concatenates each new line onto that same entry with `this._responseQueue[len - 1] += '\\n' + lines[i]`. On every iteration it calls `isPartialResponse(lastline)`, which evaluates `/^\\d+-/.test(str.slice(str.","public_affected_ranges":[">= 3.0.0, <= 10.0.9"]},{"certainty":"source_listed","source_ids":["sr-d7bfc797a4cb342bbc09755281d921ab"],"technology":"nodemailer","known_exclusions":[],"conditions_summary":"## Summary\n\nThe SMTP client response parser reassembles multiline server replies by appending each continuation line onto a single response-queue entry and re-testing whether that entry is still a partial (continuation) reply on every line. The partial-response test runs `str.slice(str.lastIndexOf('\\n') + 1)` on the growing entry, which forces a full flatten of the entire accumulated string on each line. A malicious or compromised SMTP server (or an on-path attacker on a plaintext or pre-STARTTLS hop) that streams continuation lines and never sends a completion line drives O(n^2) CPU on the single-threaded Node.js event loop before any authentication, freezing the whole process for an attacker-controlled duration.\n\n## Root Cause\n\nThe invariant that a server cannot cause superlinear client-side work while a reply is being reassembled is violated. In `src/smtp-connection/index.ts`, `_onData` splits inbound bytes into lines and, while the last queued entry is a continuation reply, concatenates each new line onto that same entry with `this._responseQueue[len - 1] += '\\n' + lines[i]`. On every iteration it calls `isPartialResponse(lastline)`, which evaluates `/^\\d+-/.test(str.slice(str.","public_affected_ranges":["SEMVER: introduced 3.0.0; fixed 10.0.10"]}],"null_published_at":"2026-11-03T22:39:43.354Z","source_updated_at":"2026-10-27T15:04:35.000Z","source_disclosed_at":"2026-10-27T15:04:33.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T22:06:46.371Z"},{"id":"NVI-00010567","kind":"vulnerability","title":"Nodemailer: Quadratic (O(n^2)) SMTP client reply parsing lets a malicious server or MITM cause a pre-auth remote denial of service","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4g23-2xm8-66gc"],"plain_summary":"GitHub lists this reviewed advisory for nodemailer. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-45ba386d5eb278648ce871f4415e8d3a"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-27T15:04:35.000Z","value":"5.9 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-45ba386d5eb278648ce871f4415e8d3a"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-45ba386d5eb278648ce871f4415e8d3a","url":"https://github.com/advisories/GHSA-4g23-2xm8-66gc","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4g23-2xm8-66gc","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:06:46.371Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-45ba386d5eb278648ce871f4415e8d3a"],"technology":"nodemailer","known_exclusions":[],"conditions_summary":"## Summary\n\nThe SMTP client response parser reassembles multiline server replies by appending each continuation line onto a single response-queue entry and re-testing whether that entry is still a partial (continuation) reply on every line. The partial-response test runs `str.slice(str.lastIndexOf('\\n') + 1)` on the growing entry, which forces a full flatten of the entire accumulated string on each line. A malicious or compromised SMTP server (or an on-path attacker on a plaintext or pre-STARTTLS hop) that streams continuation lines and never sends a completion line drives O(n^2) CPU on the single-threaded Node.js event loop before any authentication, freezing the whole process for an attacker-controlled duration.\n\n## Root Cause\n\nThe invariant that a server cannot cause superlinear client-side work while a reply is being reassembled is violated. In `src/smtp-connection/index.ts`, `_onData` splits inbound bytes into lines and, while the last queued entry is a continuation reply, concatenates each new line onto that same entry with `this._responseQueue[len - 1] += '\\n' + lines[i]`. On every iteration it calls `isPartialResponse(lastline)`, which evaluates `/^\\d+-/.test(str.slice(str.","public_affected_ranges":[">= 3.0.0, <= 10.0.9"]}],"null_published_at":"2026-10-31T22:27:09.622Z","source_updated_at":"2026-10-27T15:04:35.000Z","source_disclosed_at":"2026-10-27T15:04:33.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T22:06:46.371Z"}],"next_cursor":null,"snapshot_revision":"42594"}