CVE-2026-123204

medium

Description

Posta 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.

References

https://www.vulncheck.com/advisories/posta-before-0.18.0-ssrf-via-webhook-url

https://github.com/goposta/posta/releases/tag/v0.18.0

https://github.com/goposta/posta/pull/315

https://github.com/goposta/posta/issues/282

https://github.com/goposta/posta/commit/6bb376b55dcfdcb979040ed42c4bf57b99e4f46a

https://github.com/goposta/posta/blob/8c3cb6f89c8a992329fac21491c38aed70d05c73/internal/services/webhook/dispatcher.go#L321-L338

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-117649

Details

Source: Mitre, NVD

Published: 2026-11-05

Updated: 2026-11-05

Risk Information

CVSS v2

Base Score: 4

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 4.3

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Severity: Medium

CVSS v4

Base Score: 5.3

Vector: 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

Severity: Medium

EPSS

EPSS: 0.00302