Adserver: Authorization Bypass Through User-Controlled Key
CVE-2026-107247 is a high-severity authorization bypass through user-controlled key vulnerability in Adserver from Revive, with a CVSS 3.0 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Adserver versions: 6.0.0 through 6.0.8. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Adserver you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (hackerone.com).
Official description
An authorization bypass in Revive Adserver 6.0.0 through 6.0.8 allows an authenticated manager restricted to one agency to access or modify resources belonging to another agency. Global input registration gives GET parameters precedence over POST parameters, while submitted administration forms use POST values. By supplying authorized object identifiers in the query string and different identifiers in the POST body, an attacker can cause permission checks and subsequent operations to target different objects. This permits unauthorized cross-agency changes, campaign ownership reassignment and disclosure of campaign and banner data. The regression was introduced in commit 156dee7bc3283c128f35e5a31bb305054cc8de1b and is fixed in Revive Adserver 6.0.9 by restoring POST precedence in global input registration.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authorization Bypass Through User-Controlled Key
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.
How developers prevent this class of flaw
- For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- 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.
- 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.
More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Adserver
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.3 High severity
- 7.5 High severity
Recent Authorization Bypass Through User-Controlled Key vulnerabilities
- 9.1 Critical severity
- 8.2 High severity
- 8.7 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.6 High severity
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