CVE-2026-81303 (CVSS 6.3)

Description

A flaw was found in hawtio-operator. The operator holds routes/custom-host:create permission cluster-wide and writes the tenant-supplied spec.routeHostName value from the Hawtio custom resource directly into the Route spec without validation or authorization checks. A namespace edit user, who normally cannot set custom Route hostnames, can use the operator as a confused deputy to claim arbitrary externally-routable hostnames, enabling subdomain takeover and, in combination with the auto-grant OAuthClient, OAuth redirect hijack.

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CVSS v3.1 Score

6.3

MEDIUM

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

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.20%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-441 CWE-441

References

Other References

https://access.redhat.com/security/cve/CVE-2026-81303 https://bugzilla.redhat.com/show_bug.cgi?id=2524897

Frequently Asked Questions

What is CVE-2026-81303? +

A flaw was found in hawtio-operator. The operator holds routes/custom-host:create permission cluster-wide and writes the tenant-supplied spec.routeHostName value from the Hawtio custom resource directly into the Route spec without validation or authorization checks. A namespace edit user, who normally cannot set custom Route hostnames, can use the operator as a confused deputy to claim arbitrary externally-routable hostnames, enabling subdomain takeover and, in combination with the auto-grant OAuthClient, OAuth redirect hijack. It has a CVSS v3.1 base score of 6.3 (MEDIUM).

How severe is CVE-2026-81303? +

CVE-2026-81303 has a CVSS v3.1 score of 6.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-81303? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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