VulnerabilityPublished 17 Mar 2026

CVE-2025-62320: HCL Sametime · Cross-site Scripting

Affects HCL SametimeSource CVE Database V5

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Not known to be exploited · CVSS 4.7 Medium.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

4.7Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% 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:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: None
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: None: There is no loss of integrity within 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 17 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
HCLSametime	Affected =version 25.1.1 and below.	Fixed in–

AI-suggested

To mitigate CVE-2025-62320, organizations should prioritize upgrading HCL Sametime to versions above 25.1.1 once patches become available from HCL. In the interim, administrators can implement strict input validation and output encoding on all user-supplied data rendered in web pages to prevent injection of malicious HTML or scripts. Employing Content Security Policy (CSP) headers can help restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. User awareness training to recognize suspicious links and avoid clicking untrusted URLs can reduce exploitation likelihood. Network-level protections such as web application firewalls (WAFs) configured with rules to detect and block XSS payloads may provide additional defense. Regular security assessments and code reviews focusing on input sanitization practices in custom integrations with Sametime are recommended. Monitoring logs for unusual user activity or error messages related to input handling can aid early detection of exploitation attempts.

Description

HTML Injection can be carried out in Product when a web application does not properly check or clean user input before showing it on a webpage. Because of this, an attacker may insert unwanted HTML code into the page. When the browser loads the page, it may automatically interact with external resources included in that HTML, which can cause unexpected requests from the user’s browser.

Impact

The primary impact of CVE-2025-62320 is the potential compromise of user confidentiality within HCL Sametime environments. Attackers exploiting this XSS vulnerability can execute malicious scripts in the context of the victim’s browser, potentially stealing session tokens, user credentials, or other sensitive information accessible via the browser. This can lead to unauthorized access to user accounts or internal resources. Although the vulnerability does not directly affect system integrity or availability, the resulting unauthorized actions or data exposure can have significant operational and reputational consequences. Organizations using HCL Sametime for critical collaboration may face increased risk of targeted phishing or social engineering attacks leveraging this vulnerability. The requirement for user interaction somewhat limits the attack vector, but the widespread use of collaboration tools increases the likelihood of successful exploitation. The absence of known exploits in the wild currently reduces immediate risk, but the vulnerability remains a concern until patched.

Summary

CVE-2025-62320 is a cross-site scripting (XSS) vulnerability classified under CWE-79 affecting HCL Sametime, a widely used enterprise collaboration platform. The vulnerability exists because the application fails to properly sanitize or neutralize user-supplied input before embedding it into dynamically generated web pages. This improper input handling allows an attacker to inject arbitrary HTML or script code into pages viewed by other users. When a victim’s browser loads the compromised page, the injected code can execute in the context of the vulnerable site, potentially leading to unauthorized actions such as session hijacking, cookie theft, or redirecting users to malicious sites. The vulnerability affects all versions of HCL Sametime up to and including 25.1.1. Exploitation requires no privileges and can be performed remotely over the network, but it does require user interaction, such as clicking a malicious link or visiting a crafted page. The CVSS v3.1 base score is 4.7, indicating a medium severity level. The scope is changed (S:C), meaning the vulnerability can affect resources beyond the vulnerable component, but the impact is limited to confidentiality loss without affecting integrity or availability. No public exploits have been reported yet, but the vulnerability poses a risk to organizations relying on HCL Sametime for internal communications and collaboration. Proper input validation and output encoding are essential to prevent exploitation.

CWE-79Improper Neutralization of Input During Web Page Generation (Cross-site Scripting) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0129460 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Mar 2026, 12:42 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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