CVSS v3.1 Metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HEPSS Prediction
Documented as more likely to be exploited than 89.8% of known CVEs.
Jul 21, 2026
Jul 24, 2026
Threat Analysis
DD-WRT contains a stack-based buffer overflow vulnerability that could allow an unauthenticated attacker to overflow an internal buffer used by UPnP and trigger a code execution vulnerability.
Remediation Directive
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
External Intelligence
This vulnerability affects a common open-source component, third-party library, proprietary implementation, or a protocol used by different products. Please check with specific vendors for information on patching status. For more information, please see:
https://svn.dd-wrt.com/changeset/45724
CISA Advisory
https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
CISA Advisory
https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
National Vulnerability Database
https://nvd.nist.gov/vuln/detail/CVE-2021-27137