VulnerabilityPublished 24 Feb 2026

CVE-2026-0402: SonicWall SonicOS · Out-of-bounds Read

Affects SonicWall SonicOSSource CVE Database V5

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Not known to be exploited · CVSS 4.9 Medium.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 33% 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:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
SonicWallSonicOS	Affected =7.0.1-5169 and older versions =7.3.1-7013 and older versions =8.1.0-8017 and older versions	Fixed in–

AI-suggested

Organizations should immediately audit and restrict administrative access to SonicWall devices, ensuring only trusted personnel can authenticate. Implement network segmentation and VPNs to limit access to management interfaces. Monitor firewall logs and system stability for signs of exploitation attempts or crashes. Maintain up-to-date backups of firewall configurations to enable rapid recovery. Engage with SonicWall support to track patch release schedules and apply firmware updates promptly once available. Consider deploying additional perimeter defenses to reduce the risk of attackers gaining authenticated access. Employ multi-factor authentication for firewall management accounts to reduce the likelihood of credential compromise. Conduct regular vulnerability assessments and penetration testing to identify potential exposure. Document incident response plans specifically for firewall outages to minimize downtime.

Description

A post-authentication Out-of-bounds Read vulnerability in SonicOS allows a remote attacker to crash a firewall.

Impact

The primary impact of CVE-2026-0402 is denial-of-service against SonicWall firewall devices, which can disrupt network traffic filtering and security enforcement. Organizations relying on affected SonicOS versions may experience temporary loss of firewall protection, potentially exposing internal networks to threats or causing business disruption. Critical infrastructure, enterprises, and service providers using SonicWall firewalls could face operational outages. Although confidentiality and integrity are not directly compromised, the availability impact can indirectly increase risk by disabling security controls. The requirement for authenticated access limits the threat to insiders or attackers who have already breached perimeter defenses. However, once exploited, the attacker can cause repeated firewall crashes, complicating incident response and recovery. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as patches are not yet available.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

psirt.global.sonicwall.com/vuln-detail/SNWLID-2026-0001 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Feb 2026, 20:56 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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