CVE-2025-40596VulnerabilityPublished 23 Jul 2025Updated 26 Feb 2026

CVE-2025-40596: SonicWall SMA 100 Series · Stack-based Buffer Overflow

Affects SonicWall SMA 100 SeriesSource CVE Database V5

Not known to be exploited · 44% EPSS · CVSS 7.3 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.3High

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

EPSS: 44.9% chance of exploitation in 30 days – higher than 98% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-25.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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

AI-suggested

1. Immediately restrict access to the SonicWall SMA 100 Series web interface by implementing network segmentation and firewall rules to limit management interface exposure to trusted IP addresses only. 2. Monitor network traffic and device logs for unusual or suspicious activity indicative of exploitation attempts, such as malformed HTTP requests targeting the web interface. 3. Disable or limit remote management features if not strictly necessary, reducing the attack surface. 4. Implement intrusion detection and prevention systems (IDS/IPS) with signatures or heuristics capable of detecting buffer overflow attempts against SonicWall devices. 5. Regularly check for and apply official patches or firmware updates from SonicWall as soon as they become available to remediate the vulnerability. 6. Employ multi-factor authentication (MFA) on management interfaces where possible to add an additional layer of security, even though this vulnerability does not require authentication. 7. Conduct internal audits to inventory all SonicWall SMA 100 Series devices and verify firmware versions to prioritize patching and mitigation efforts. 8. Educate IT and security teams about this vulnerability to ensure rapid response and incident handling if exploitation is suspected.

Description

A Stack-based buffer overflow vulnerability in the SMA100 series web interface allows remote, unauthenticated attacker to cause Denial of Service (DoS) or potentially results in code execution.

Impact

The impact of CVE-2025-40596 is substantial for organizations relying on SonicWall SMA 100 Series devices for secure remote access and VPN connectivity. Exploitation can lead to denial of service, disrupting critical network access and business operations. More severe consequences include remote code execution, which could allow attackers to execute arbitrary commands, potentially leading to full device compromise, lateral movement within networks, data exfiltration, or deployment of further malware. The vulnerability threatens confidentiality, integrity, and availability of affected systems. Given the unauthenticated and remote nature of the exploit, attackers can target exposed devices over the internet without prior access, increasing the attack surface. Organizations in sectors such as government, finance, healthcare, and critical infrastructure, which often deploy SonicWall appliances, face heightened risks. Additionally, compromised devices could be leveraged as entry points for broader network intrusions or as part of botnets. The absence of known exploits in the wild currently provides a window for proactive defense, but the risk of future exploitation remains high.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
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)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

psirt.global.sonicwall.com/vuln-detail/SNWLID-2025-0012 (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 27 Feb 2026, 01:59 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

Related threats