ETK-2026-1851Zero's internal tracking ID, independent of the CVE number.
validatedZero produced an exploit or a check.description
FreeScout versions through 1.8.247 can process concurrent redemptions of the same valid invitation as separate successful activations. An attacker who possesses a live invitation URL may obtain an authenticated session for the invited account by racing the intended recipient; this can include administrator access when the invitation is for an administrator.
mitigation
Upgrade freescout-helpdesk/freescout to version 1.8.248 or later. Until upgrading, revoke and reissue exposed or untrusted outstanding invitations and limit access to invitation URLs.
fixed in 1.8.248
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.
- 2026-10-17 05:04Zghsa: trigger signal, started the run
this entry in the feed
GET /api/v1/feed/ETK-2026-1851
{ "etk_id": "ETK-2026-1851", "cve_id": null, "display_id": "ETK-2026-1851", "ghsa_id": "GHSA-c8rg-2r2h-5vgc", "euvd_id": null, "status": "published", "anchor_state": "awaiting_cve", "title": "Invitation redemption race condition in FreeScout", "summary": "FreeScout versions through 1.8.247 can process concurrent redemptions of the same valid invitation as separate successful activations. An attacker who possesses a live invitation URL may obtain an authenticated session for the invited account by racing the intended recipient; this can include administrator access when the invitation is for an administrator.", "mitigation": "Upgrade freescout-helpdesk/freescout to version 1.8.248 or later. Until upgrading, revoke and reissue exposed or untrusted outstanding invitations and limit access to invitation URLs.", "vendor": "composer", "product": "composer:freescout-helpdesk/freescout", "affected": [ { "affected_notes": [], "affected_ranges": [ "<1.8.248" ], "ecosystem": "composer", "fixed_versions": [ "1.8.248" ], "package_name": "freescout-helpdesk/freescout", "purl": "pkg:composer/freescout-helpdesk/freescout" } ], "cwes": [ 362 ], "cvss_score": 7.5, "cvss_src": "cna_vendor", "cvss_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "epss_score": null, "epss_percentile": null, "epss_asof": null, "automation": "deterministic", "check": true, "check_confidence_basis": "differential", "exploit": false, "pipeline_minutes": 29.409895133333332, "t0_at": null, "signals": { "check": { "at": "2026-10-17T05:41:16.381154+00:00", "days": -3.889252956145833, "is_lower_bound": true, "measured_at": "2026-10-21T03:01:47.869922+00:00", "url": null }, "trigger_signal": { "at": "2026-10-17T05:04:34+00:00", "days": -3.914743478761574, "is_lower_bound": true, "measured_at": "2026-10-21T03:01:47.869922+00:00", "url": "https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-c8rg-2r2h-5vgc" } } }
published 2026-10-17 05:11Z
last change 2026-10-21 02:54Z
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