CVE•Published 2026-10-27•Modified 2026-10-27•0 articles on news•6 live references•NVD data
CVE-2026-117553
Vulnerability data via NVD (ingested)
CVSS v3.1
7.5
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS percentile
—
Weaknesses (CWE)
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.
Timeline
Published 2026-10-27
Modified 2026-10-27
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2026-117553Hosts Shodan has explicitly fingerprinted as vulnerable.
More intel sources (5)
Shodan report
vuln:CVE-2026-117553Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-117553Censys host search filtered to this CVE id.
grep.app
CVE-2026-117553Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-117553GitHub code search for direct mentions.
Google dork
"CVE-2026-117553" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-117553 on GitHub.
We haven't classified any articles referencing CVE-2026-117553 yet. The external references above still apply.