CVEvulnerability

CVE-2026-117553

7.7 HIGH Published 2026-10-27 Modified 2026-10-27 Official page ↗
Status
Awaiting Analysis
Published
2026-10-27
Last modified
2026-10-27
Assigner
[email protected]
CVSS 4.0 ([email protected])
7.7 HIGH — CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/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
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Weaknesses
CWE-601

Description

Umbraco CMS before 17.7.2 and 18.2.2 contains an authentication bypass vulnerability that allows unauthenticated attackers to register attacker-controlled OAuth redirect URIs by poisoning the Host header. Attackers send signed-in users authorization links using response_mode=form_post to capture codes, then redeem them via HTTP Basic client credentials to hijack back-office sessions and execute code through Razor templates.

Related

Weakness · CWE (1)

  • CWE-601 URL Redirection to Untrusted Site weakness

References