Cisco IOS XR Open Port Vulnerability
Cisco IOS XR software health check opens TCP port 6379 by default on activation. An attacker can connect to the Redis instance on the open port and allow access to the Redis instance that is running within the NOSi container.
- Vendor
- Cisco
- Product
- IOS XR
- CVSS
- 6.5
- EPSS (exploit probability)
- 11.5%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2022-20821 being exploited?
Yes. CISA added CVE-2022-20821 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 11.5% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-19. Full cross-catalog view: /kev-comparison
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Cisco IOS XR CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2010-3035 Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability | [ HIGH ] | 7.5 | 5.7% | |
| CVE-2009-2055 Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability | [ MEDIUM ] | 5.9 | 3.3% | |
| CVE-2020-3569 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability | [ HIGH ] | 8.6 | 3.3% | |
| CVE-2020-3566 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability | [ HIGH ] | 8.6 | 3.7% | |
| CVE-2020-3118 Cisco IOS XR Software Discovery Protocol Format String Vulnerability | [ HIGH ] | 8.8 | 11.7% |