Vulnerability · Published Oct 15, 2026 · Assigned by VulnCheck

CVE-2026-111358SendPortal sendportal-core through 4.0.1 Cross-Workspace Tag Attachment via Subscriber Form

Medium 5.4

In plain English

A medium-severity authorization bypass via user-controlled key in sendportal-core from mettle. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.3%top 75.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

SendPortal sendportal-core through 4.0.1 contains an authorization bypass vulnerability that allows authenticated workspace members to attach subscribers to other workspaces' tags by supplying unvalidated tag IDs. Attackers can submit sequential tag IDs via the web subscriber form or CSV import to receive victim campaign content and skew victim reports.

Affected products (as reported)

Vendor	Product	Versions
mettle	sendportal-core	0 – through 4.0.1

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References

https://hackmd.io/@hieuPenguinnn/sendportal-subscriber-tags-cross-workspace-attach third-party-advisory
https://github.com/mettle/sendportal-core/blob/v4.0.1/src/Repositories/Subscribers/BaseSubscriberTenantRepository.php#L48-L51 technical-description
https://github.com/mettle/sendportal-core/blob/v4.0.1/src/Http/Requests/SubscriberRequest.php#L34-L37 technical-description
https://github.com/mettle/sendportal-core product
VulnCheck Advisory: SendPortal sendportal-core through 4.0.1 Cross-Workspace Tag Attachment via Subscriber Form third-party-advisory