CVE-2026-21640 Denial of service in Revive Adserver
An attacker can disable the admin console by injecting specific characters into settings, causing a fatal PHP error.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21640?
CVE-2026-21640 is a low-severity denial of service vulnerability in Revive Adserver, published on 20 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
HackerOne community member Faraz Ahmed (PakCyberbot) has reported a format string injection in the Revive Adserver settings. When specific character combinations are used in a setting, the admin user console could be disabled due to a fatal PHP error.
Weakness: CWE-134
Which versions are affected by CVE-2026-21640?
It affects 1 product.
Products include Aquaplatform Revive Adserver.
How do I fix CVE-2026-21640?
No fix has been published for CVE-2026-21640 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-21640 being exploited?
There is no known exploitation of CVE-2026-21640 in the wild and no public exploit code.
Other vulnerabilities in Revive Adserver
Sources
Also known as GHSA-cr56-64wj-q2r7.