{"items":[{"id":"NVI-00010609","kind":"vulnerability","title":"Nodemailer: Quadratic backtracking in SMTP AUTH mechanism detection regexes allows pre-auth remote denial of service","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4ffr-jq9g-5ffx","CVE-2026-110869"],"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-6a5c11f0c420019c2163e104c93fb255"],"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 10.0.13 for nodemailer. Confirm the publisher’s latest guidance.","source_ids":["sr-7fc2fbd93ae632858a33b7251234d56a"],"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":"2026-10-27T15:04:41.000Z","value":"5.9 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-6a5c11f0c420019c2163e104c93fb255"}],"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-6a5c11f0c420019c2163e104c93fb255","url":"https://github.com/advisories/GHSA-4ffr-jq9g-5ffx","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4ffr-jq9g-5ffx","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:06:46.371Z"},{"id":"sr-7fc2fbd93ae632858a33b7251234d56a","url":"https://github.com/advisories/GHSA-4ffr-jq9g-5ffx","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-4ffr-jq9g-5ffx","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-11-03T09:59:02.656Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-6a5c11f0c420019c2163e104c93fb255"],"technology":"nodemailer","known_exclusions":[],"conditions_summary":"## Summary\n\nNodemailer's SMTP client applies four regular expressions to a peer's EHLO response to detect the supported SASL mechanisms. Each pattern uses an alternation with two overlapping whitespace-matching sub-patterns, which produces quadratic (O(n^2)) backtracking whenever the mechanism name is absent from the line. A malicious or MITM SMTP server that answers EHLO with `250-AUTH` followed by a long whitespace-only run and a non-matching token blocks the Node.js event loop for tens of seconds to hours during a pre-authentication handshake. No authentication to the target SMTP server is required, and any application that connects to an attacker-influenced host is affected.\n\n## Root Cause\n\nEach of the four AUTH mechanism regexes in `SMTPConnection._actionEHLO` contains the sub-pattern `(?:(\\s+|=)[^\\n]*\\s+|\\s+|=)` before the mechanism literal. `[^\\n]*` and the trailing `\\s+` both match whitespace and can consume the same characters, so when the mechanism literal is absent, the regex engine must try every partition of the whitespace run between `[^\\n]*` and `\\s+` before failing. The four regexes run unconditionally on every EHLO response, with no length cap, no shape validation,","public_affected_ranges":[">= 3.0.0, <= 10.0.12"]},{"certainty":"source_listed","source_ids":["sr-7fc2fbd93ae632858a33b7251234d56a"],"technology":"nodemailer","known_exclusions":[],"conditions_summary":"## Summary\n\nNodemailer's SMTP client applies four regular expressions to a peer's EHLO response to detect the supported SASL mechanisms. Each pattern uses an alternation with two overlapping whitespace-matching sub-patterns, which produces quadratic (O(n^2)) backtracking whenever the mechanism name is absent from the line. A malicious or MITM SMTP server that answers EHLO with `250-AUTH` followed by a long whitespace-only run and a non-matching token blocks the Node.js event loop for tens of seconds to hours during a pre-authentication handshake. No authentication to the target SMTP server is required, and any application that connects to an attacker-influenced host is affected.\n\n## Root Cause\n\nEach of the four AUTH mechanism regexes in `SMTPConnection._actionEHLO` contains the sub-pattern `(?:(\\s+|=)[^\\n]*\\s+|\\s+|=)` before the mechanism literal. `[^\\n]*` and the trailing `\\s+` both match whitespace and can consume the same characters, so when the mechanism literal is absent, the regex engine must try every partition of the whitespace run between `[^\\n]*` and `\\s+` before failing. The four regexes run unconditionally on every EHLO response, with no length cap, no shape validation,","public_affected_ranges":["SEMVER: introduced 3.0.0; fixed 10.0.13"]}],"null_published_at":"2026-11-03T22:39:43.351Z","source_updated_at":"2026-10-27T15:04:41.000Z","source_disclosed_at":"2026-10-27T15:04:39.000Z","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-00010609","kind":"vulnerability","title":"Nodemailer: Quadratic backtracking in SMTP AUTH mechanism detection regexes allows pre-auth remote denial of service","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-4ffr-jq9g-5ffx"],"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-6a5c11f0c420019c2163e104c93fb255"],"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":"2026-10-27T15:04:41.000Z","value":"5.9 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-6a5c11f0c420019c2163e104c93fb255"}],"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-6a5c11f0c420019c2163e104c93fb255","url":"https://github.com/advisories/GHSA-4ffr-jq9g-5ffx","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-4ffr-jq9g-5ffx","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T22:06:46.371Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-6a5c11f0c420019c2163e104c93fb255"],"technology":"nodemailer","known_exclusions":[],"conditions_summary":"## Summary\n\nNodemailer's SMTP client applies four regular expressions to a peer's EHLO response to detect the supported SASL mechanisms. Each pattern uses an alternation with two overlapping whitespace-matching sub-patterns, which produces quadratic (O(n^2)) backtracking whenever the mechanism name is absent from the line. A malicious or MITM SMTP server that answers EHLO with `250-AUTH` followed by a long whitespace-only run and a non-matching token blocks the Node.js event loop for tens of seconds to hours during a pre-authentication handshake. No authentication to the target SMTP server is required, and any application that connects to an attacker-influenced host is affected.\n\n## Root Cause\n\nEach of the four AUTH mechanism regexes in `SMTPConnection._actionEHLO` contains the sub-pattern `(?:(\\s+|=)[^\\n]*\\s+|\\s+|=)` before the mechanism literal. `[^\\n]*` and the trailing `\\s+` both match whitespace and can consume the same characters, so when the mechanism literal is absent, the regex engine must try every partition of the whitespace run between `[^\\n]*` and `\\s+` before failing. The four regexes run unconditionally on every EHLO response, with no length cap, no shape validation,","public_affected_ranges":[">= 3.0.0, <= 10.0.12"]}],"null_published_at":"2026-10-31T22:27:09.625Z","source_updated_at":"2026-10-27T15:04:41.000Z","source_disclosed_at":"2026-10-27T15:04:39.000Z","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"}