VulnerabilityPublished 4 Mar 2026

CVE-2026-20057: Cisco Cyber Vision · Divide By Zero

Affects Cisco Cyber VisionSource CVE Database V5

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Not known to be exploited · CVSS 5.8 Medium · patch available : update Cisco Cyber Vision when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

5.8Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: None
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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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: 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 4 Mar 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
CiscoCisco Cyber Vision	Affected >=4.2.0 <4.3.0 – 5.3.1 53 affected builds	Fixed in–
CiscoCisco Secure Firewall Threat Defense (FTD) Software	Affected 7.2.0 – 7.7.10.1 37 affected builds	Fixed in–
CiscoCisco UTD SNORT IPS Engine Software	Affected 17.12.1a – 17.18.2 27 affected builds	Fixed in–

AI-suggested

1. 2. If you cannot patch yet, implement network segmentation to isolate Cisco Cyber Vision devices from untrusted networks, reducing exposure to crafted VBA data packets. 3. Deploy strict ingress filtering and deep packet inspection on network segments hosting Cisco Cyber Vision to detect and block malformed VBA data or suspicious traffic patterns targeting the Snort 3 engine. 4. Consider temporarily disabling or restricting the VBA feature within Snort 3 if feasible, to prevent processing of potentially malicious VBA data. 5. Maintain comprehensive monitoring and alerting on Cisco Cyber Vision system health to detect unexpected restarts or crashes promptly. 6. Conduct regular backups of configuration and monitoring data to enable rapid recovery in case of service disruption. 7. Engage with Cisco support for guidance on interim mitigations and best practices tailored to your deployment environment. 8. Educate security teams about this vulnerability to ensure rapid incident response if exploitation attempts are detected.

Description

Multiple Cisco products are affected by a vulnerability in the Snort 3 Visual Basic for Applications (VBA) feature which could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash.    This vulnerability is due to lack of proper error checking when decompressing VBA data. An attacker could exploit this vulnerability by sending a crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to unexpectedly restart causing a a denial of service (DoS) condition.

Impact

The primary impact of CVE-2026-20057 is a denial of service condition caused by the Snort 3 Detection Engine crashing and restarting. This disrupts the continuous monitoring and detection capabilities of Cisco Cyber Vision, potentially leaving industrial and critical infrastructure networks blind to threats during the downtime. Organizations relying on Cisco Cyber Vision for real-time visibility into operational technology (OT) environments may experience reduced situational awareness, increasing the risk of undetected attacks or operational failures. While confidentiality and integrity remain unaffected, the loss of availability can have cascading effects, particularly in sectors such as manufacturing, energy, utilities, and transportation where Cisco Cyber Vision is commonly deployed. The ease of remote exploitation without authentication or user interaction increases the risk of automated attacks or scanning by threat actors. Although no known exploits exist currently, the vulnerability’s presence across many versions and the critical role of the affected product in network security elevate the potential impact globally.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3-vbavuls-96UcVVed (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Mar 2026, 20:09 UTC

Technical details

References

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