CVE-2020-5135
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.
Key facts
- CVSS score
- 9.8 (v3.1)
- Severity
- CRITICAL
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
- CWE-120
- EPSS score
- 26.9% (98th percentile)
- In CISA KEV
- Yes, added March 15, 2022
- In EU EUVD
- Yes (EUVD-2020-26382)
- Published
- October 12, 2020
- NVD last modified
- June 17, 2026
- Status
- Analyzed
CISA Known Exploited Vulnerability
SonicWall SonicOS Buffer Overflow Vulnerability
Added to the KEV catalog on March 15, 2022; federal remediation due April 5, 2022. Known to be used in ransomware campaigns.
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2020-26382 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on October 21, 2025.
View on the EU Vulnerability DatabaseAffected products
- sonicwall / sonicos
- sonicwall / sonicos
- sonicwall / sonicosv
Certified products that may be affected
3 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.
- SonicWall SonicOS Enhanced V6.5.4 with VPN and IPS on TZ and SOHO Appliances - SonicWALL, Inc - Common Criteria CCEVS-VR-11028-2020 - archived
- SonicOS Enhanced V5.9.0 - SonicWALL, Inc - Common Criteria CSEC2013004 - archived
- SonicWALL SonicOS Enhanced v5.9.0 on NSA Series and TZ Series Appliances - SonicWALL, Inc - Common Criteria 383-4-224 - archived
References
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2020-0010(Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-5135(US Government Resource)
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
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