CVE-2026-100858

7.6 HIGH 0.3% exploit odds Fix listed Disclosure Server

What it is

heym before 0.0.109 contains a server-side request forgery vulnerability in the Slack, Discord, and Crawler workflow nodes. These nodes issue HTTP requests to URLs taken from user-created credentials (webhook_url / flaresolverr_url) using an unguarded HTTP client, bypassing the SSRF egress guard that already protects the HTTP, WebSocket, and MCP nodes; the credential API validates only that the URL is non-empty. Any registered user can create a credential pointing at an internal address and execute a workflow, causing the backend to reach loopback, private, link-local, or cloud-metadata endpoints and return the full response body in the node output (non-blind SSRF).

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-27 00:20 UTC ReservedThe CVE id was reserved by its CNA
2026-09-27 02:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-30 16:17 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 7.6 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-27 02:17 UTC
Last modified: 2026-09-30 16:17 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-918 · Server-side request forgery
Record status: Deferred

Attack profile CVSS 4.0 · 7.6

Attack vector: Network
Complexity: High
Attack requirements: Present
Privileges needed: Low
User interaction: None
Confidentiality: High
Integrity: High
Availability: None

Raw vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-100858.md and follow it. Check whether this project is affected by CVE-2026-100858. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record