What EVULNABLE says
Listed in the CISA KEV catalog, and Confirmed exploitation in the wild.
Patch This Cycle
CVE-2021-27137
DD-WRT — DD-WRT Stack-Based Buffer Overflow Vulnerability
CISA KEV · in the CISA KEV catalog since 2026-07-21
The priority band answers “how soon”, not “how bad” — see Methodology for what it weighs and where it abstains.
The evidence behind it
| Measure | Value | Source |
|---|---|---|
| CVSS base score | 8.1 | NVD |
| FIRST EPSS | 0.040 (89.8th pctl) | FIRST |
| Actively exploited | Confirmed | CISA KEV |
| Ransomware campaign use | Unknown or none | CISA KEV |
| CISA remediation deadline | 2026-07-24 — Overdue by 45 days | CISA KEV |
What CISA says to do
- 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 ↗
- BOD 26-04 ↗
- Forensics Triage Requirements ↗
- nvd.nist.gov/…/CVE-2021-27137 ↗
The primary records
This page is an opinion about urgency. Where it and a source of record disagree, the source of record is the record.
Where this sits
CVE-2021-27137 is one of the entries ranked on the priority feed and in the non-Microsoft advisories.