High
FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force
Type: advisorySources: OSV
FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, attachment download tokens are generated using a weak and predictable formula: `md5(APP_KEY + attachment_id + size)`. Since attachment_id is sequential and size can be brute-forced in a small range, an unauthenticated attacker can forge valid tokens and download any private attachment without credentials. Version 1.8.213 fixes the issue.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-40496
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 15:06 UTC · Revision 1
Source evidence
FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force
core-osv · Original sourcePublished 21 Apr 2026, 01:38 UTC
FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, attachment download tokens are generated using a weak and predictable formula: `md5(APP_KEY + attachment_id + size)`. Since attachment_id is sequential and size can be brute-forced in a small range, an unauthenticated attacker can forge valid tokens and download any private attachment without credentials. Version 1.8.213 fixes the issue.
osv:CVE-2026-40496
Complete source record
{
"id": "f22bfb7ebacea385ea005476bab071e5ea6b5198d29f8b7ebc720af2afb2c9fb",
"url": "https://osv.dev/vulnerability/CVE-2026-40496",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "FreeScout has Predictable Attachment Token that Allows Unauthenticated Private File Download via Brute Force",
"summary": "FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, attachment download tokens are generated using a weak and predictable formula: `md5(APP_KEY + attachment_id + size)`. Since attachment_id is sequential and size can be brute-forced in a small range, an unauthenticated attacker can forge valid tokens and download any private attachment without credentials. Version 1.8.213 fixes the issue.",
"evidence": "osv:CVE-2026-40496",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-40496",
"aliases": [
"CVE-2026-40496",
"GHSA-2783-wxmm-wmwr"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/freescout-help-desk/freescout",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "acf57a7a4b19544641523c6f7e51b1035c03c9b6"
},
{
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}
],
"database_specific": {
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{
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"range": [
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{
"fixed": "1.8.213"
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"source": "CPE_RANGE"
},
{
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"source": "REFERENCES_COMMIT"
},
{
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}
}
],
"modified": "2026-10-28T02:30:51.061861159Z",
"provider": "osv",
"references": [
"https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40496.json",
"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-2783-wxmm-wmwr",
"https://nvd.nist.gov/vuln/detail/CVE-2026-40496",
"https://github.com/freescout-help-desk/freescout/commit/dbdf8f2260b43a21818255c70f0b61b9de9cd555"
],
"provider_metadata": {
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],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40496.json"
}
},
"related_cves": [
{
"value": "CVE-2026-40496",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 519713,
"published_at": "2026-04-21T01:38:50.117+00:00"
}