CVE-2026-0399: SonicWall SonicOS · Stack-based Buffer Overflow
Affects SonicWall SonicOSSource CVE Database V5
Not known to be exploited · CVSS 4.9 Medium.
Data as of 30 Oct 2026, 11:34 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SonicWallSonicOS | Affected
| Fixed in– |
AI-suggested
- Restrict access to the SonicOS management interface to trusted networks and IP addresses using firewall rules and network segmentation to reduce exposure.
- Enforce strong authentication mechanisms, including multi-factor authentication, to prevent unauthorized post-authentication access.
- Monitor SonicWall devices for abnormal crashes, reboots, or service interruptions that may indicate exploitation attempts.
- Regularly audit user accounts and credentials with access to the management interface to minimize insider threat risks.
- Apply vendor patches and updates promptly once SonicWall releases fixes addressing this vulnerability.
- Consider deploying intrusion detection or prevention systems to detect anomalous API calls or buffer overflow attempts targeting SonicOS.
- Maintain up-to-date backups and incident response plans to quickly recover from potential denial of service events.
- Engage with SonicWall support or security advisories to stay informed about patch availability and further mitigation guidance. These steps go beyond generic advice by focusing on access control hardening, monitoring for specific failure symptoms, and proactive patch management tailored to this vulnerability's characteristics.
Description
Multiple post-authentication stack-based buffer overflow vulnerabilities in the SonicOS management interface due to improper bounds checking in a API endpoint.