VulnerabilityPublished 15 Apr 2026

CVE-2026-20059: Cisco Unity Connection · Cross-site Scripting

Affects Cisco Unity ConnectionSource CVE Database V5

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Not known to be exploited · CVSS 6.1 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

6.1Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: 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: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Apr 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 Unity Connection	Affected 14 – 15SU4 12 affected builds	Fixed in–

AI-suggested

Until an official fix is available, users should exercise caution when clicking links related to the Cisco Unity Connection management interface. Network-level protections such as web filtering or intrusion prevention systems may help reduce exposure to malicious links. Monitor Cisco's security advisories for updates on patches or official mitigations.

Description

A vulnerability in the web-based management interface of Cisco Unity Connection could allow an unauthenticated, remote attacker to conduct a reflected XSS attack against a user of the interface. This vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

Impact

Successful exploitation allows an attacker to execute arbitrary script code in the context of the Cisco Unity Connection web interface, potentially leading to disclosure of sensitive browser-based information or manipulation of the interface. The impact is limited to confidentiality and integrity with no availability impact. The vulnerability requires user interaction (clicking a crafted link) and does not require authentication.

Summary

This vulnerability in Cisco Unity Connection's web management interface is due to improper neutralization of input during web page generation, resulting in a reflected XSS condition. An unauthenticated attacker can exploit this by persuading a user to click a maliciously crafted URL, causing arbitrary script execution within the user's browser session on the management interface. This can lead to disclosure of sensitive information accessible via the browser or manipulation of the interface in the user's context. The issue affects multiple versions from 14 through 15SU4. The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, user interaction required, scope changed, and low impact on confidentiality and integrity, with no impact on availability. Cisco has published the vulnerability but has not yet provided an official fix or remediation.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-unity-vulns-n2EJSbbw (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 15 Apr 2026, 16:33 UTC

Technical details

References

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