ETK-2026-4448Zero's internal tracking ID, independent of the CVE number.
validatedZero produced an exploit or a check.description
FreeScout versions before 1.8.251 can associate an inbound email with an existing helpdesk conversation using an insufficiently validated message identifier. An attacker who knows an identifier from a customer's message can take over the conversation, view subsequent replies, and impersonate the customer to support staff. Exploitation requires the installation to fetch email from a mailbox.
mitigation
Upgrade FreeScout to version 1.8.251 or later. Until upgraded, restrict access to helpdesk mailboxes and treat externally supplied message-threading headers as untrusted.
fixed in 1.8.251
outcome
Check only, differential: the check fires on the vulnerable build and is silent on the patched one.
source signals
Public signals that triggered or updated the pipeline. These are inputs for the deltas above.
- 2026-11-14 06:59Zghsa: trigger signal, started the run
this entry in the feed
GET /api/v1/feed/ETK-2026-4448
{ "etk_id": "ETK-2026-4448", "cve_id": null, "display_id": "ETK-2026-4448", "ghsa_id": "GHSA-6q4w-p2f4-q8q8", "euvd_id": null, "status": "published", "anchor_state": "awaiting_cve", "title": "Unauthenticated email conversation takeover in FreeScout", "summary": "FreeScout versions before 1.8.251 can associate an inbound email with an existing helpdesk conversation using an insufficiently validated message identifier. An attacker who knows an identifier from a customer's message can take over the conversation, view subsequent replies, and impersonate the customer to support staff. Exploitation requires the installation to fetch email from a mailbox.", "mitigation": "Upgrade FreeScout to version 1.8.251 or later. Until upgraded, restrict access to helpdesk mailboxes and treat externally supplied message-threading headers as untrusted.", "vendor": null, "product": "FreeScout", "affected": [ { "affected_notes": [], "affected_ranges": [ "<1.8.251" ], "ecosystem": null, "fixed_versions": [ "1.8.251" ], "package_name": "FreeScout", "purl": null } ], "cwes": [ 290 ], "cvss_score": 9.1, "cvss_src": "cna_vendor", "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "epss_score": null, "epss_percentile": null, "epss_asof": null, "automation": "deterministic", "check": true, "check_confidence_basis": "differential", "exploit": false, "pipeline_minutes": 46.196977, "t0_at": null, "signals": { "check": { "at": "2026-11-14T07:58:08.012834+00:00", "days": -0.01095565679398148, "is_lower_bound": true, "measured_at": "2026-11-14T08:13:54.679104+00:00", "url": null }, "trigger_signal": { "at": "2026-11-14T06:59:05+00:00", "days": -0.05196274978009259, "is_lower_bound": true, "measured_at": "2026-11-14T08:13:54.679104+00:00", "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-6q4w-p2f4-q8q8" } } }
published 2026-11-14 07:11Z
last change 2026-11-14 08:13Z
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