CVE-2026-123204 · Package
NO FIX YET · SEE WHAT TO DO
Posta before v0.18.0 lets a logged-in user with edit rights create webhooks pointing at arbitrary URLs, and the server sends POST requests to them. An attacker can aim these at loopback, private-network or cloud metadata addresses and read status codes and error strings to map internal hosts and ports.
first public Nov 5, 2026 · 1 source
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Teams that self-host Posta before v0.18.0 and let more than a small set of trusted users edit workspaces. The server has to be able to reach internal networks or cloud metadata endpoints for the probe to return useful data. Deployments on v0.18.0 or later, or where only trusted administrators can create webhooks, are lower risk.
Not affected if managed-hosting, version-0.18.0-or-later
Who cares posta, self-hosted, webhooks
posta --version or the image tag, and check whether it is below 0.18.00.18.0 or laterPosta before v0.18.0 contains a server-side request forgery vulnerability that allows authenticated users with edit rights to make the backend send POST requests to internal destinations by creating webhooks with arbitrary URLs. Attackers can target loopback, private-network or cloud metadata addresses and read delivery status codes and error strings to probe internal hosts and ports.
This page as .md · .json · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/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
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