VulnerabilityPublished 30 Mar 2026

CVE-2026-3321: ON24 Q&A chat · Insecure Direct Object Reference

Affects ON24 Q&A chatSource CVE Database V5

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Not known to be exploited · CVSS 8.7 High.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

8.7High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: Low
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system 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 Subsequent System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 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 30 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
ON24ON24 Q&A chat	Affected All versions	Fixed in–

AI-suggested

To mitigate CVE-2026-3321, organizations should first monitor for any updates or patches released by ON24 and apply them promptly once available. In the absence of official patches, implement network-level controls such as restricting access to the vulnerable API endpoint using firewall rules or API gateways to allow only trusted IP addresses or authenticated users. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious enumeration patterns targeting the 'console-survey/api/v1/answer/' endpoint. Conduct thorough logging and monitoring of API access to detect anomalous requests indicative of exploitation attempts. Review and harden access control policies within ON24 configurations to ensure minimal exposure of sensitive data. Additionally, consider isolating the ON24 environment from critical internal systems to limit lateral movement opportunities if a breach occurs. Educate event administrators and security teams about the vulnerability and encourage vigilance for unusual activity. Finally, perform regular security assessments and penetration tests focusing on API endpoints to identify similar authorization weaknesses.

Description

A vulnerability of authorization bypass through user-controlled key in the 'console-survey/api/v1/answer/{EVENTID}/{TIMESTAMP}/' endpoint. Exploiting this vulnerability would allow an unauthenticated attacker to enumerate event IDs and obtain the complete Q&A history. This publicly exposed data may include IDs, private URLs, private messages, internal references, or other sensitive information that should only be exposed to authenticated users. In addition, the leaked content could be exploited to facilitate other malicious activities, such as reconnaissance for lateral movement, exploitation of related systems, or unauthorised access to internal applications referenced in the content of chat messages.

Impact

The impact of CVE-2026-3321 is significant for organizations using ON24 Q&A chat, especially those handling sensitive or confidential information during events. Unauthorized access to Q&A histories can lead to data breaches exposing private communications, internal URLs, and references to internal systems. This exposure can facilitate further attacks such as lateral movement within corporate networks, targeted phishing, or exploitation of referenced internal applications. The breach of confidentiality can damage organizational reputation, lead to regulatory compliance violations, and cause financial losses. Since the vulnerability requires no authentication and can be exploited remotely, the attack surface is broad, increasing the likelihood of exploitation. Organizations relying on ON24 for webinars, virtual events, or customer engagement are particularly at risk, as attackers can harvest sensitive event data without detection. The lack of known exploits in the wild currently reduces immediate risk but does not diminish the potential for future attacks.

CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

incibe.es/en/incibe-cert/notices/aviso/authorization-bypass-on24-qa-chat (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Mar 2026, 13:53 UTC

WeaknessesCWE-639

Technical details

References

Community reviews

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