TrueConf Client Download of Code Without Integrity Check
CVE-2026-3502 is a high-severity download of code without integrity check vulnerability in TrueConf Client from TrueConf, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited from the same local network by an attacker with administrator privileges, but only if a user takes part, for example by opening a link or file. Affected TrueConf Client versions: TrueConf Client versions 8.1.0 through 8.5.2. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on April 2, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Trueconf to 8.5.3.884 or a later version.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| TrueConf | TrueConf Client | TrueConf Client versions 8.1.0 through 8.5.2 | Not stated |
| Trueconf | Trueconf | before 8.5.3.884 | 8.5.3.884 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L. Scored by CNA (checkpoint.com).
Official description
TrueConf Client downloads application update code and applies it without performing verification. An attacker who is able to influence the update delivery path can substitute a tampered update payload. If the payload is executed or installed by the updater, this may result in arbitrary code execution in the context of the updating process or user.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Download of Code Without Integrity Check
The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.
How developers prevent this class of flaw
- Perform proper forward and reverse DNS lookups to detect DNS spoofing.
- Encrypt the code with a reliable encryption scheme before transmitting.
- Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
More Download of Code Without Integrity Check vulnerabilities (CWE-494)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- trueconf.com/blog/update/trueconf-8-5Product, Release Notes
Third-party and government advisories
Recent Download of Code Without Integrity Check vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
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